[Federal Register Volume 70, Number 161 (Monday, August 22, 2005)]
[Proposed Rules]
[Pages 49094-49138]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-16385]



[[Page 49093]]

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Part IV





Environmental Protection Agency





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40 CFR Part 141



Unregulated Contaminant Monitoring Regulation (UCMR) for Public Water 
Systems Revisions; Proposed Rule

  Federal Register / Vol. 70, No. 161 / Monday, August 22, 2005 / 
Proposed Rules  

[[Page 49094]]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 141

[Docket No. OW-2004-0001; FRL-7954-8]
RIN 2040-AD93


Unregulated Contaminant Monitoring Regulation (UCMR) for Public 
Water Systems Revisions

AGENCY: Environmental Protection Agency.

ACTION: Proposed rule.

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SUMMARY: The Safe Drinking Water Act (SDWA), as amended in 1996, 
requires the United States Environmental Protection Agency (EPA) to 
establish criteria for a program to monitor unregulated contaminants 
and to publish a list of contaminants to be monitored every five years. 
EPA published such a list for the first Unregulated Contaminant 
Monitoring Regulation cycle (i.e., UCMR 1) and a revised approach for 
UCMR implementation in the Federal Register dated September 17, 1999. 
UCMR 1 established a three-tiered approach for monitoring contaminants 
based on the availability of analytical methods and laboratory capacity 
considerations. Today's proposed regulation meets the SDWA requirement 
to publish a listing of unregulated contaminants every five years.
    Today's action proposes the design for the second UCMR cycle. EPA 
is proposing to require monitoring of 26 chemicals using nine different 
analytical methods. UCMR 2 monitoring is proposed to occur during 2007-
2011.This proposed action builds on the established structure of UCMR 1 
and proposes some changes to the rule design. The primary changes to 
UCMR 1 include: Redesign of the Screening Survey for List 2 
contaminants to increase the statistical strength of the sampling 
results by incorporating additional PWSs; updates to the lists of 
contaminants to be monitored and the analytical methods approved to 
conduct that monitoring; revisions to the ``data elements'' required to 
be reported; and some revisions to the implementation of the monitoring 
program to reflect ``lessons learned'' during UCMR 1. A systematic 
procedure for the determination of a Minimum Reporting Level (MRL) is 
also being proposed.
    Implementation of today's proposed action would benefit the 
environment by providing EPA and other interested parties with 
scientifically valid data on the occurrence of these contaminants in 
drinking water, permitting the assessment of the population potentially 
being exposed and the levels of that exposure. These data are the 
primary source of occurrence and exposure data for the Agency to 
determine whether to regulate these contaminants.

DATES: Written comments must be postmarked by midnight, delivered by 
hand, or electronically mailed on or before October 21, 2005.

ADDRESSES: Submit your comments, identified by Docket ID No. OW-2004-
0001, by one of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the on-line instructions for submitting comments.
     Agency Web site: http://www.epa.gov/edocket. EDOCKET, 
EPA's electronic public docket and comment system, is EPA's preferred 
method for receiving comments. Follow the on-line instructions for 
submitting comments.
     E-mail: [email protected].
     Mail: Send three copies of your comments and any 
enclosures to: Water Docket, United States Environmental Protection 
Agency, Mail Code 4101T, 1200 Pennsylvania Avenue, NW., Washington, DC 
20460, Attention Docket ID No. OW-2004-0001. Commenters should use a 
separate paragraph for each issue discussed. In addition, please mail a 
copy of your comments on the information collection provisions to the 
Office of Information and Regulatory Affairs, Office of Management and 
Budget (OMB), Attn: Desk Officer for EPA, 725 17th St., NW., 
Washington, DC 20503.
     Hand Delivery: Deliver your comments to Water Docket, EPA 
Docket Center, Environmental Protection Agency, Room B102, 1301 
Constitution Ave., NW., Washington, DC, Attention Docket ID No. OW-
2004-0001. Such deliveries are only accepted during the Docket's normal 
hours of operation, and special arrangements should be made for 
deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. OW-2004-0001. 
EPA's policy is that all comments received will be included in the 
public docket without change and may be made available online at http://www.epa.gov/edocket, including any personal information provided, 
unless the comment includes information claimed to be Confidential 
Business Information (CBI) or other information whose disclosure is 
restricted by statute. Do not submit information that you consider to 
be CBI or otherwise protected through EDOCKET, http://www.regulations.gov, or e-mail. The EPA EDOCKET and the http://www.regulations.gov Web sites are ``anonymous access'' systems, which 
means EPA will not know your identity or contact information unless you 
provide it in the body of your comment. If you send an e-mail comment 
directly to EPA without going through EDOCKET or http://www.regulations.gov, your e-mail address will be automatically captured 
and included as part of the comment that is placed in the public docket 
and made available on the Internet. If you submit an electronic 
comment, EPA recommends that you include your name and other contact 
information in the body of your comment and with any disk or CD-ROM you 
submit. If EPA cannot read your comment due to technical difficulties 
and cannot contact you for clarification, EPA may not be able to 
consider your comment. Electronic files should avoid the use of special 
characters, any form of encryption, and be free of any defects or 
viruses. For additional information about EPA's public docket visit 
EDOCKET on-line or see the Federal Register of May 31, 2002 (67 FR 
38102 (USEPA, 2002c)).
    Docket: All documents in the docket are listed in the EDOCKET index 
at http://www.epa.gov/edocket. Although listed in the index, some 
information is not publicly available, i.e., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, is not placed on the Internet and will be 
publicly available only in hard copy form. Publicly available docket 
materials are available either electronically in EDOCKET or in hard 
copy at the Water Docket, EPA/DC, EPA West, Room B102, 1301 
Constitution Avenue, NW., Washington, DC. This Public Reading Room is 
open from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding 
legal holidays. The telephone number for the Public Reading Room is 
(202) 566-1744, and the Water Docket is (202) 566-2426.

FOR FURTHER INFORMATION CONTACT: Gregory Carroll, Technical Support 
Center, Office of Ground Water and Drinking Water, United States 
Environmental Protection Agency, Office of Water, 26 West Martin Luther 
King Drive (MS 140), Cincinnati, OH 45268, telephone (513) 569-7948; or 
e-mail at [email protected]. For general information, contact the 
Safe Drinking Water Hotline. Callers within the United States may reach 
the Hotline at (800) 426-4791. The Hotline is open Monday through 
Friday, excluding legal holidays, from 9 a.m. to 5 p.m. eastern time.

SUPPLEMENTARY INFORMATION:

[[Page 49095]]

I. General Information

A. Does This Action Apply to Me?

    Entities regulated by this action are public water systems (PWSs). 
All large community and non-transient non-community water systems 
serving more than 10,000 people will be required to monitor. A 
community water system means a PWS which serves at least 15 service 
connections used by year-round residents or regularly serves at least 
25 year-round residents. Non-transient non-community water system means 
a PWS that is not a community water system and that regularly serves at 
least 25 of the same people over 6 months per year. Only a nationally 
representative sample of community and non-transient non-community 
systems serving 10,000 or fewer people will be required to monitor. 
Transient non-community systems (i.e., systems that do not regularly 
serve at least 25 of the same people over 6 months per year) will not 
be required to monitor. States, territories, and tribes with primary 
enforcement responsibility (primacy) to administer the regulatory 
program for PWSs under the Safe Drinking Water Act (SDWA) may 
participate in the implementation of the second cycle of the 
Unregulated Contaminant Monitoring Regulation (i.e., UCMR 2) through a 
Partnership Agreement. These Primacy agencies may choose to conduct 
analyses to measure for contaminants in water samples collected for the 
UCMR 2; in which case they will be regulated by this action. Regulated 
categories and entities are identified in the following table.

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                                    Examples of potentially
             Category                 regulated entities      NAICS \a\
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State, local, & tribal             States, local and tribal       924110
 governments.                       governments that
                                    analyze water samples
                                    on behalf of public
                                    water systems required
                                    to conduct such
                                    analysis; states, local
                                    and tribal governments
                                    that directly operate
                                    community and non-
                                    transient non-community
                                    water systems required
                                    to monitor.
Industry.........................  Private operators of           221310
                                    community and non-
                                    transient non-community
                                    water systems required
                                    to monitor.
Municipalities...................  Municipal operators of        924110
                                    community and non-
                                    transient non-community
                                    water systems required
                                    to monitor.
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\a\ NAICS = North American Industry Classification System.

    This table is not intended to be exhaustive, but rather provides a 
guide for readers regarding entities likely to be regulated by this 
action. This table lists the types of entities that the EPA is now 
aware may potentially be regulated by this action. Other types of 
entities not listed in the table could also be regulated. To determine 
whether your facility is regulated by this action, you should carefully 
examine the definition of PWS in Sec.  141.2 of Title 40 of the Code of 
Federal Regulations, and applicability criteria in Sec.  141.40(a)(1) 
and (2) of today's proposed action. If you have questions regarding the 
applicability of this action to a particular entity, consult the person 
listed in the preceding FOR FURTHER INFORMATION CONTACT section.

B. What Should I Consider as I Prepare My Comments for EPA?

1. Submitting Confidential Business Information
    Do not submit this information to EPA through EDOCKET, http://www.regulations.gov, or e-mail. Clearly mark the part or all of the 
information that you claim to be confidential business information 
(CBI). For CBI information in a disk or CD-ROM that you mail to EPA, 
mark the outside of the disk or CD-ROM as CBI and then identify 
electronically within the disk or CD-ROM the specific information that 
is claimed as CBI. In addition to one complete version of the comment 
that includes information claimed as CBI, a copy of the comment that 
does not contain the information claimed as CBI must be submitted for 
inclusion in the public docket. Information so marked will not be 
disclosed except in accordance with procedures set forth in 40 CFR part 
2.
2. Tips for Preparing Your Comments
    When submitting comments, remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree; suggest alternatives 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible, avoiding the 
use of profanity or personal threats.
     Make sure to submit your comments by the comment period 
deadline identified.

Abbreviations and Acronyms

245-HBB 2,2',4,4',5,5'-hexabromobiphenyl
[mu]g/L Microgram per liter
ADI Acceptable daily intake
ASDWA Association of State Drinking Water Administrators
ATSDR Agency for Toxic Substances and Disease Registry
BDE-47 2,2',4,4'-tetrabromodiphenyl ether
BDE-99 2,2',4,4',5-pentabromodiphenyl ether
BDE-100 2,2',4,4',6-pentabromodiphenyl ether
BDE-153 2,2',4,4',5,5'-hexabromodiphenyl ether
CBI Confidential Business Information
CCL Contaminant Candidate List
CF Concentration fortified
CFR Code of Federal Regulations
CWS Community water system
DBP Disinfection Byproduct
DBPR Stage 1 Disinfection Byproducts Rule
DEA Desethylatrazine
DACT Diaminochlorotriazine or Desethyldesisopropylatrazine.
DIA Desisopropylatrazine
DQO Data quality objective
DSMRT Distribution system maximum residence time
EPA United States Environmental Protection Agency
EPTDS Entry point to the distribution system
ESA Ethane sulfonic acid
FACA Federal Advisory Committee Act
FR Federal Register
FS Field sample
g/kg Gram per kilogram
GWUDI Ground water under the direct influence of surface water
HRPIR Half range prediction interval of results
HSDB Hazardous Substances Database

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IARC International Agency for Research on Cancer
ICR Information collection request
IDC Initial demonstration of capability
IRIS Integrated Risk Information System
LCMRL Lowest concentration minimum reporting level
LD50 Median lethal dose
LFSM Laboratory fortified sample matrix
LFSMD Laboratory fortified sample matrix duplicate
MCL Maximum contaminant level mg/kg Milligram per kilogram
mg/kg/day Milligram per kilogram per day mg/L Milligram per liter
MRL Minimum reporting level
NCOD National Drinking Water Contaminant Occurrence Database
NDBA N-nitroso-di-n-butylamine
NDEA N-nitroso-diethylamine
NDMA N-nitroso-dimethylamine
NDPA N-nitroso-di-n-propylamine
NMEA N-nitroso-methylethylamine
NPDWR National Primary Drinking Water Regulation
NPYR N-nitroso-pyrrolidine
NTNCWS Non-transient non-community water system
NTTAA National Technology Transfer and Advancement Act
OA Oxanilic acid
OMB Office of Management and Budget
ORD Office of Research and Development
PA Partnership agreement
PBB Polybrominated biphenyls
PBDE Polybrominated diphenyl ethers pH Negative log of the hydrogen ion 
concentration
PIR Prediction interval of results
PT Proficiency testing
PWS Public water system
PWSID Public water system identification
QC Quality control
RDX Hexahydro-1,3,5-trinitro-1,3,5-triazine
RED Reregistration Eligibility Decision
RFA Regulatory Flexibility Act
RfD Reference dose
RPD Relative percent difference
SBA Small Business Administration
SDWA Safe Drinking Water Act
SRF State Revolving Fund
TBBPA Tetrabromobisphenol A
TDI Tolerable daily intake
TNT 2,4,6-trinitrotoluene
TRI Toxics Release Inventory
UCMR Unregulated Contaminant Monitoring Regulation
UMRA Unfunded Mandates Reform Act of 1995
USGS United States Geological Survey
USEPA United States Environmental Protection Agency

Table of Contents

I. General Information
    A. Does This Action Apply to Me?
    B. What Should I Consider as I Prepare My Comments for EPA?
    1. Submitting Confidential Business Information
    2. Tips for Preparing Your Comments
II. Statutory Authority and Background
    A. What Is the Statutory Authority for UCMR?
    B. How Does EPA Meet These Statutory Requirements?
    C. How Are the Contaminant Candidate List, the National 
Contaminant Occurrence Database, and the UCMR Interrelated?
III. Requirements of the Unregulated Contaminant Monitoring Program
    A. What Priority Contaminants Were Selected for UCMR 2?
    1. Compilation of Initial List of UCMR 2 Candidates
    2. Establishing Priorities for UCMR 2
    a. Health Effects Prioritization Approach.
    b. Selections Based on UCMR 1 Reserved Contaminants List.
    i. Alachlor ethane sulfonic acid (ESA) and Other Degradation 
Products of Acetanilide Pesticides--List 2.
    ii. Explosives--List 1.
    c. Selections from UCMR 1 Contaminants List.
    d. Selection of Emerging Contaminants.
    i. Nitrosamines--List 2.
    ii. Others Identified in CCL 1 Process and Recent Reviews of 
Information on Emerging Contaminants--List 1.
    3. Other Considerations in Selecting Contaminants
    a. Triazine Chlorodegradates and Parent Compounds.
    b. Other Contaminants Considered.
    B. What Analytical Methods Will Be Used for Monitoring?
    C. How Were These Analytical Methods Developed?
    D. How Were Minimum Reporting Levels Determined?
    E. How Will Laboratories Conduct UCMR Analyses?
    1. Laboratory Approval Process for UCMR 2
    a. Request to Participate.
    b. Registration.
    c. Application Package.
    d. EPA Review of Application Package.
    e. Proficiency Testing.
    f. Written EPA Approval.
    2. Quality Control Requirements
    F. How Are Systems Selected for UCMR Monitoring?
    1. How Are Systems Selected for Assessment Monitoring?
    a. Original Assessment Monitoring Statistical Approach for UCMR 
1.
    b. Proposed Assessment Monitoring Statistical Approach for UCMR 
2.
    2. How Are Systems Selected for the Screening Survey?
    a. Original Screening Survey Statistical Approach for UCMR 1.
    b. Proposed Screening Survey Statistical Approach for UCMR 2.
    3. What Is UCMR Pre-Screen Testing?
    4. What Are the Other Applicability Considerations?
    a. New Applicability Date.
    b. Notice Regarding Changes to Applicability Required.
    c. Definition of System Population.
    G. When Must Monitoring Be Conducted?
    1. Timing of Monitoring
    2. Individual PWS Monitoring Schedules
    H. Where Are Samples Collected?
    I. What Is the States' Role in the UCMR Program?
    1. State Participation in Partnership Agreements (PAs)
    2. Activities To Be Included in the UCMR 2 PAs
    a. Review and Revision of the Initial State Monitoring Plan.
    b. Review and Approval of PWS Proposed Representative EPTDS.
    c. Notification and Instructions for Systems.
    3. What If States Do Not Participate in a PA?
    J. What Are the Data Reporting Requirements?
    1. What Information Is Required Prior to Monitoring?
    a. Contact Information.
    b. Sampling Location and Inventory Information.
    c. Proposals for Ground Water Representative Sampling Locations.
    2. When Must Monitoring Results Be Reported?
    a. Large Systems.
    b. Small Systems.
    3. What Data Elements Are Required with the Monitoring Results?
    a. New Data Elements.
    b. Unchanged Data Elements.
    c. Modified Data Elements.
    d. Data Elements No Longer Reported.
    K. Time Line of UCMR Activities
    1. Assessment Monitoring
    2. Screening Survey
IV. Cost and Benefits of Today's Proposed Action
V. Technical Corrections
VI. Statutory and Executive Order Reviews
    A. Executive Order 12866: Regulatory Planning and Review
    B. Paperwork Reduction Act
    C. Regulatory Flexibility Act
    D. Unfunded Mandates Reform Act
    E. Executive Order 13132: Federalism
    F. Executive Order 13175: Consultation and Coordination With 
Indian Tribal Governments
    G. Executive Order 13045: Protection of Children From 
Environmental Health and Safety Risks
    H. Executive Order 13211: Actions That Significantly Affect 
Energy Supply, Distribution, or Use
    I. National Technology Transfer and Advancement Act
    J. Executive Order 12898: Federal Actions To Address 
Environmental Justice in Minority Populations and Low-Income 
Populations
VII. Public Involvement in Regulation Development
VIII. References

PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS

Sec.  141.24 Organic chemical, sampling and analytical requirements.

[[Page 49097]]

Sec.  141.35 Reporting for unregulated contaminant monitoring.
    (a) General applicability.
    (b) Reporting by all systems.
    (1) Where to submit UCMR reporting requirement information.
    (2) Contacting EPA if your system does not meet applicability 
criteria or has status change.
    (c) Reporting by large systems.
    (1) Contact information.
    (2) Sampling location and inventory information.
    (3) Proposed ground water representative sampling locations.
    (i) Qualifications.
    (ii) Demonstration.
    (iii) Approval.
    (4) Contacting EPA if your PWS has not been notified of 
requirements.
    (5) Notifying EPA if your PWS cannot sample according to 
schedule.
    (6) Reporting monitoring results.
    (i) Electronic reporting system.
    (ii) Reporting schedule.
    (7) Only one set of results accepted.
    (8) No reporting of previously collected data.
    (d) Reporting by small systems.
    (1) Contact information.
    (2) Reporting sampling information.
    (e) Data elements.
Sec.  141.40 Monitoring requirements for unregulated contaminants.
    (a) General applicability.
    (1) Applicability to transient non-community systems.
    (2) Applicability to community water systems and non-transient 
non-community water systems.
    (i) Large systems.
    (ii) Small systems.
    (3) Analytes to be monitored.
    (4) Sampling requirements.
    (i) Large systems.
    (ii) Small systems.
    (5) Quality control requirements.
    (i) Sample collection/preservation.
    (ii) Laboratory approval for Lists 1 and 2.
    (iii) Minimum Reporting Level.
    (iv) Laboratory fortified sample matrix and laboratory fortified 
sample matrix duplicate.
    (v) Detection Confirmation.
    (vi) Method defined quality control.
    (vii) Reporting.
    (6) Violation of this rule.
    (i) Monitoring violations.
    (ii) Reporting violations.
    (b) Requirements for State and Tribal participation.
    (1) Governors' petition for additional contaminants.
    (2) State-wide waivers.
    (i) Application.
    (ii) Approval.

List of Exhibits and Tables

Preamble

Exhibit 1: Proposed Contaminant List and Sampling Design
Exhibit 2: Summary of Proposed Major Changes to UCMR 1
Exhibit 3: Median Lethal Dose and Corresponding Toxicity Ranking
Exhibit 4: Comparison of Acetanilide Herbicides Use
Exhibit 5: Analytes Included in the Explosives Method (EPA 529)
Exhibit 6: Analytical Methods Proposed for UCMR 2 Monitoring
Exhibit 7: Approximate Sample Allocation for Assessment Monitoring: 
Expected Number of Systems Selected by System Size and Water Source
Exhibit 8: UCMR 1 Design Allocation of Systems for Screening 
Surveys, by Size Category
Exhibit 9: Allocation of Systems for Screening Survey, List 2 
Contaminants
Exhibit 10: Time Line of UCMR Activities
Exhibit 11: Systems To Participate in UCMR 2 Monitoring
Exhibit 12: Number of Publicly- and Privately-Owned Systems Subject 
to UCMR 2
Exhibit 13: EPA and Small Systems Costs for Implementation UCMR 2
Exhibit 14: UCMR 2 Relative Cost Analysis for Publicly-Owned Systems 
(2007-2011)
Exhibit 15: UCMR 2 Relative Cost Analysis for Privately-Owned 
Systems (2007-2011)

Sec.  141.35

Table 1. Unregulated Contaminant Monitoring Reporting Requirements

Sec.  141.40

Table 1. UCMR Contaminant List
Table 2. Monitoring Frequency by Contaminant and Water Source Types
Table 3. The Constant Factor (C) to be Multiplied by the Standard 
Deviation to Determine the Half Range Interval of the PIR (Student's 
t 99% Confidence Level)

II. Statutory Authority and Background

A. What Is the Statutory Authority for UCMR?

    Section 1445(a)(2) of the Safe Drinking Water Act (SDWA), as 
amended in 1996, requires that once every five years, beginning in 
August 1999, the United States Environmental Protection Agency (EPA) 
issue a new list of no more than 30 unregulated contaminants to be 
monitored by PWSs, and that EPA enter the monitoring data into a 
national contaminant occurrence database. EPA's UCMR program must 
ensure that only a national representative sample of public water 
systems (PWSs) serving 10,000 or fewer people will be required to 
monitor; however, there are no such restrictions on the number of 
systems serving more than 10,000 people. EPA must vary the frequency 
and schedule for monitoring based on the number of systems served, the 
source of supply, and the contaminants likely to be found.

B. How Does EPA Meet These Statutory Requirements?

    To fulfill the initial SDWA requirements, EPA published ``Revisions 
to the Unregulated Contaminant Monitoring Regulation for Public Water 
Systems; Final Rule,'' on September 17, 1999 (64 FR 50556, (USEPA, 
1999c)). Several supplemental rules were published to establish 
analytical methods and to provide clarifications and refinements to the 
initial rule: 65 FR 11372, March 2, 2000 (USEPA, 2000a); 66 FR 2273, 
January 11, 2001 (USEPA, 2001a); and 67 FR 65888, October 29, 2002 
(USEPA, 2002d).\1\ SDWA, as amended in 1996, requires that at least 
once every five years EPA identify a list of no more than 30 
unregulated contaminants to be monitored. Today's action fulfills this 
statutory obligation, identifying 26 priority contaminants for 
monitoring using nine proposed analytical methods. To comply with SDWA, 
EPA has developed a proposed contaminant list (Exhibit 1) and sampling 
design for UCMR 2 (2007-2011) with input from both stakeholders and an 
EPA working group.
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    \1\ Additional technical corrections to the rule, as well as 
adjustments to the initial reporting process, were published 
including: May 16, 2001 (66 FR 27215 (USEPA, 2001b)); September 4, 
2001 (66 FR 46221 (USEPA, 2001d)); and March 12, 2002 (67 FR 11043 
(USEPA, 2002b)). In total, these rules and revisions constitute the 
``UCMR 1.'' This amendment to establish new contaminants for 
monitoring during the second five-year cycle is referred to as 
``UCMR 2.''

        Exhibit 1.--Proposed Contaminant List and Sampling Design
------------------------------------------------------------------------
 
------------------------------------------------------------------------
                      List 1. Assessment Monitoring
------------------------------------------------------------------------
1,3-dinitrobenzene........................  2,4,6-trinitrotoluene (TNT).
2,2',4,4'-tetrabromodiphenyl ether (BDE-    Dimethoate.
 47).
2,2',4,4',5-pentabromodiphenyl ether (BDE-  Hexahydro-1,3,5-trinitro-
 99).                                        1,3,5-triazine (RDX).
2,2',4,4',5,5'-hexabromobiphenyl (245-HBB)  Terbufos sulfone.
2,2',4,4',5,5'-hexabromodiphenyl ether      Perchlorate.
 (BDE-153).

[[Page 49098]]

 
2,2',4,4',6-pentabromodiphenyl ether (BDE-  ............................
 100).
-------------------------------------------
                        List 2. Screening Survey
------------------------------------------------------------------------
Acetochlor................................  Metolachlor OA.
Acetochlor ESA............................  N-nitroso-diethylamine
                                             (NDEA).
Acetochlor OA.............................  N-nitroso-dimethylamine
                                             (NDMA).
Alachlor..................................  N-nitroso-di-n-butylamine
                                             (NDBA).
Alachlor ESA..............................  N-nitroso-di-n-propylamine
                                             (NDPA).
Alachlor OA...............................  N-nitroso-methylethylamine
                                             (NMEA).
Metolachlor...............................  N-nitroso-pyrrolidine
                                             (NPYR).
Metolachlor ESA...........................  ............................
------------------------------------------------------------------------

    The UCMR for the first cycle of monitoring (i.e., UCMR 1) 
established a three-tiered approach for monitoring contaminants based 
on the availability of analytical methods. Assessment Monitoring 
contaminants on List 1 (UCMR 1) could be analyzed using analytical 
methods that were in common use in drinking water laboratories. 
Screening Survey contaminants on List 2 (UCMR 1) could only be analyzed 
using newly developed analytical methods that were not in common use in 
drinking water laboratories. Laboratory capacity to perform these 
analyses was therefore limited. No analytical methods were available to 
monitor for the Pre-Screen Survey contaminants on List 3 (UCMR 1), 
although the regulation allowed for the possibility of such methods 
becoming available during the cycle.
    EPA has developed the design for the second UCMR cycle (i.e., UCMR 
2). EPA is building upon the established structure of UCMR 1, and 
proposing some changes to the rule design, based upon lessons learned 
during the UCMR 1 cycle. The design of UCMR 2 is summarized below, 
including a discussion of the changes proposed for UCMR 2, and the 
reasons for those proposed changes.
    Assessment Monitoring (i.e., List 1) is the largest in scope of the 
three UCMR 2 monitoring components (or tiers). Under Assessment 
Monitoring, List 1 contaminants, for which standard analytical methods 
are available, are monitored to assess national occurrence in drinking 
water. These are the priority contaminants for which analytical method 
technologies are well established. EPA is proposing that Assessment 
Monitoring be required for all large water systems (those serving more 
than 10,000 people), and for a nationally representative sample of 800 
small water systems (those serving 10,000 or fewer people), during a 
continuous 12-month period during July 2007 through June 2010 quarterly 
for surface water systems, and twice, at 6-month intervals for ground 
water systems). Systems subject to UCMR 2 include community water 
systems (CWSs) and non-transient non-community water systems (NTNCWSs), 
except those systems that purchase all of their finished water from 
another PWS.
    EPA designed the sampling frame for the national sample of small 
systems to ensure that UCMR 2 sampling results would yield a high level 
of confidence and a low margin of error. To attain the representative 
sample, EPA is proposing that small systems be stratified by water 
source type (ground or surface water), service size category, and State 
(each allocated a minimum of two systems). With monitoring data from 
all large PWSs (a census of all 3,110 large systems) and a 
statistically representative sample of 800 small PWSs (for a total of 
approximately 3,910 systems), List 1 Assessment Monitoring provides 
sample data suitable for national population exposure assessments.
    The second tier of UCMR 2 is referred to as List 2 or Screening 
Survey monitoring. List 2 contaminants are those for which analytical 
methods have been recently developed, and for which the technologies 
are not widely used and, therefore, laboratory capacity may be 
insufficient to conduct the larger scale Assessment Monitoring. EPA is 
proposing that a Screening Survey be conducted by approximately 320 
PWSs serving more than 100,000 people (i.e., all systems in this 
largest size category), by a randomly selected sample of 320 PWSs 
serving between 10,001 and 100,000 people, and by 480 small PWSs. 
Screening Survey systems will be required to monitor during a 
continuous 12-month period during July 2007 through June 2009 quarterly 
for surface water systems, and twice, at 6-month intervals, for ground 
water systems). With a total of over 1,100 systems participating in the 
Screening Survey, sufficient data will be generated to provide an 
overall national estimate of population exposure.
    The third tier of UCMR 2 is called Pre-Screen Testing. Pre-Screen 
Testing is envisioned for use with methods that are in the early stages 
of development, and/or methods that are very specialized or limited in 
applicability. It is designed to be conducted by up to 200 PWSs that 
would be identified by State agencies as vulnerable to the List 3 
contaminants. This would be a targeted sampling to assess occurrence in 
the most vulnerable settings, and could help to guide the next steps 
for contaminant evaluation and methods development. EPA is not 
proposing any Pre-Screen Testing in today's action.

C. How Are the Contaminant Candidate List, the National Contaminant 
Occurrence Database, and the UCMR Interrelated?

    The UCMR program was developed in coordination with the Contaminant 
Candidate List (CCL) and the National Drinking Water Contaminant 
Occurrence Database (NCOD). The CCL is a list of contaminants that are 
not subject to any proposed or promulgated National Primary Drinking 
Water Regulation (NPDWR), are known or anticipated to occur at PWSs, 
and may require regulation under SDWA. The first CCL, published in 
March 1998 (referred to as ``CCL 1''), identified 60 contaminants or 
contaminant groups (63 FR 10274, March 2, 1998 (USEPA, 1998b)) that 
were divided into categories to represent research and data needs for 
each of the following: (1) Regulatory determination priorities; (2) 
health effects research priorities; (3) treatment research priorities; 
(4) analytical methods research priorities; and (5) occurrence 
priorities. The data collected through the UCMR program is being stored 
in the NCOD to facilitate analysis and review of contaminant 
occurrence; to guide the conduct of the CCL process; and to support the 
Administrator's determination to regulate a contaminant in the interest 
of protecting public health, as required under SDWA section 1412(b)(1). 
Results of the UCMR 1 monitoring can be

[[Page 49099]]

viewed by the public at EPA's UCMR Web site: http://www.epa.gov/safewater/ucmr/data.html. The second CCL was published in February 2005 
and carried over many of the unregulated contaminants from CCL 1, for 
which research is ongoing (70 FR 9071, February 24, 2005 (USEPA, 2005).

III. Requirements of the Unregulated Contaminant Monitoring Program

    EPA has developed, and is proposing in today's action, a revised 
design for UCMR 2 based on experience with UCMR 1. In addition to 
requesting comments on the list of UCMR 2 contaminants, EPA is also 
requesting comments on the Agency's specification of minimum reporting 
levels (MRLs) and the procedure to establish them. Other changes for 
which EPA is requesting comment include modifications or clarifications 
to the systems required to monitor, the timing and location of 
monitoring, and the reporting process. Today's proposed modifications 
to the rule also incorporate lessons learned during the course of UCMR 
1 implementation. Throughout UCMR 1, EPA worked with States, regulated 
PWSs, and analytical laboratories in addressing implementation and 
regulatory requirements. EPA reviewed various aspects of the UCMR 1 
program and identified several critical changes that will improve 
implementation. The specific approach that EPA is proposing for UCMR 2, 
along with the rationale for any changes, is described in this section.
    Exhibit 2 provides a list of the substantive changes to UCMR 1 
being proposed in today's action. EPA invites the public to comment on 
these changes to the UCMR program. Instructions for submission of 
public comments are provided in the ADDRESSES section of this preamble. 
Key aspects of the UCMR program that remain the same include direct 
implementation of the rule by EPA, the design of Assessment Monitoring, 
and EPA funding for the small system testing (i.e., for those systems 
serving 10,000 or fewer people).
    Although EPA is republishing the entire text of 40 CFR 141.35 and 
40 CFR 141.40 of today's action for readability purposes, EPA is not 
reproposing for public comment aspects of the rule that are unchanged 
from the 1999 UCMR 1. The unchanged aspects of UCMR 1 include: (1) The 
design of Assessment Monitoring (for List 1 contaminants), except for 
the elimination of Index Systems, and Pre-Screen Testing (for List 3 
contaminants); (2) the frequency of sampling; (3) the requirement to 
resample when a sampling error occurs; (4) use of the largest 
concentration when duplicate samples are reported; (5) the requirements 
for laboratories to enter monitoring data, and large PWSs to approve 
and submit data using EPA's electronic data reporting system; (6) 
reporting of PWS contacts; (7) the definition of violations; (8) the 
opportunity for State and Tribes to enter into Partnership Agreements; 
(9) the Governors' petition process; and (10) the State-wide waiver 
provision. EPA is not seeking, and will not respond to comments on 
parts of the UCMR that are unchanged under today's action.

         Exhibit 2.--Summary of Proposed Major Changes to UCMR 1
------------------------------------------------------------------------
             Change                    Preamble              Rule
------------------------------------------------------------------------
New list of 26 priority           Contaminants:       Sec.
 contaminants, and 9 analytical    III.A.;             141.40(a)(3).
 methods.                          Analytical
                                   Methods: III.B.;
                                   III.C.
Modified laboratory approval      III.E.1...........  Sec.
 program.                                              141.40(a)(5)(ii)-
                                                       (vi).
QC requirements: Detection limit  III.E.2...........  Sec.  Sec.
 would be replaced by MRL; No                          141.40(a)(5)(iii)
 longer required to analyze a                          -(v).
 field reagent blank or QC
 sample.
Changes in timing for posting     III.E.2; III.J.2..  Sec.
 and approval of monitoring data.                      141.35(c)(6)(ii);
                                                       Sec.
                                                       141.40(a)(5)(vii)
                                                       .
Elimination of Index systems....  III.F.1.b.........  Sec.
                                                       141.40(a)(2)(ii)(
                                                       C).
More systems to monitor for       III.F.2...........  Sec.
 Screening Survey.                                     141.40(a)(2)(i)(B
                                                       ); Sec.
                                                       141.40(a)(2)(ii)(
                                                       B).
Screening Survey monitoring to    III.F.2.b; III.K.2  Sec.
 be conducted across 2 years.                          141.40(a)(3).
Establishment of date for rule    III.F.4...........  Sec.   141.35(a);
 applicability; Clarification of                       Sec.   141.40(a).
 system population definition.
Large systems must submit         III.J.1.a.........  Sec.
 contact and sampling location                         141.35(b)(1).
 information.
Large system monitoring will be   III.G.2...........  Sec.
 scheduled by EPA with allowance                       141.35(c)(5);
 for systems to change schedule                        Sec.
 if needed.                                            141.40(a)(4)(i).
All samples collected at EPTDSs;  III.H; III.J.1.b..  Monitor at EPTDS
 nitorsamines samples for PWSs                         and DSMRT
 subject to Stage 1 D/DBP Rule                         locations: Sec.
 collected at DSMRT and EPTDS                          141.40(a)(3);
 locations; Representative EPTDS                       Sec.
 proposals by PWSs with multiple                       141.40(a)(4)(i)(C
 ground water EPTDSs.                                  ); Sec.
                                                       141.40(a)(4)(ii)(
                                                       B).
                                                      EPTDS proposal:
                                                       Sec.
                                                       141.35(c)(3).
Changes to data elements........  III.J.3...........  Sec.   141.35(e).
------------------------------------------------------------------------
Acronyms: QC = quality control; MRL = minimum reporting level; PWS =
  public water system; EPTDS = entry point to the distribution system; D/
  DBP Rule = Stage 1 Disinfectant/Disinfection Byproducts Rule; DSMRT =
  distribution system maximum residence time; UCMR = Unregulated
  Contaminant Monitoring Regulation.

A. What Priority Contaminants Were Selected for UCMR 2?

1. Compilation of Initial List of UCMR 2 Candidates
    With public health protection as its top priority, EPA has drawn 
upon several different sources in developing the proposed UCMR 2 
contaminant list. In the early stages of list development, EPA began by 
identifying a broad list of over 200 contaminants. This information and 
rationale was first presented at a public stakeholder meeting held on 
October 29, 2003, within a draft discussion document titled: ``UCMR 2: 
Contaminant Selection Rationale'' (USEPA, 2003e). The following sources 
were used to identify potential UCMR 2 contaminants:
     UCMR 1 ``reserved'' contaminants (CCL 1 occurrence 
priorities): Includes those contaminants identified as priorities in 
the September 1999 UCMR (64 FR 50556 (USEPA, 1999c)), but reserved for 
later monitoring because methods were not yet available. By design, 
most of the UCMR 1 contaminants were selected from the list of CCL 1 
contaminants that required the

[[Page 49100]]

collection of additional occurrence data and for which analytical 
methods were available (63 FR 10274 (USEPA, 1998b)).
     Other UCMR 1 contaminants: Includes several contaminants 
that were monitored under UCMR 1 and were identified as potential UCMR 
2 priorities because Screening Survey results indicate the need for 
more information, or because improved analytical methods for these 
contaminants have been developed since the last cycle.
     CCL 1 ``deferred pesticides'': Includes a list of priority 
pesticides ranked by chemical properties, occurrence, and use that EPA 
identified. EPA decided to ``defer'' certain pesticides for later 
consideration pending further evaluation of these pesticides to 
determine if they occur at levels of health concern (62 FR 52194, 
October 6, 1997 (USEPA, 1997)). EPA plans to consider the deferred 
pesticides in the context of an improved approach for selecting 
contaminants for future CCLs. This will enable the Agency to consider 
these contaminants in a consistent, reproducible manner with a wide 
range of other contaminants.
     CCL 1 suspected endocrine disruptors: Includes a list of 
chemicals that were suspected of having adverse effects on endocrine 
function (62 FR 52194, October 6, 1997 (USEPA, 1997)) that EPA 
identified during the development of CCL 1. For certain suspected 
endocrine disruptors for which little information was available, EPA 
decided to wait for further study to reconsider these contaminants in 
the future. As with pesticides, EPA believes that suspected endocrine 
disruptors should be considered in the context of an improved approach 
for selecting contaminants for future CCLs. This enables the Agency to 
use a more refined and improved approach in evaluating these 
contaminants.
     Other emerging contaminants: Includes additional 
contaminants of concern based on current research on occurrence and 
relative health effects risk factors, and whether the contaminants 
could be identified by analytical methods used in measuring other 
priority UCMR contaminants.
2. Establishing Priorities for UCMR 2
    Of the 200-plus contaminants initially identified, EPA retained 
only those contaminants that met the following criteria: (1) Pesticides 
on the list must be currently registered for use in the United States; 
(2) all contaminants must have an analytical reference standard (pure 
compound) available; and (3) the analytical method must be available. 
Based on these criteria, the list was reduced to approximately 127 
contaminants.
    EPA further prioritized this list of contaminants as follows. The 
relative health effects screening was considered as part of EPA's 
identification of contaminants for monitoring under UCMR 2 (the 
relative effects screening and prioritization process is discussed and 
explained in next section). Through this prioritization process, 26 
contaminants have been identified for UCMR 2 monitoring. At the current 
time, EPA does not expect to add contaminants to reach the statutory 
maximum of 30 contaminants. However, if other emerging contaminant(s) 
advance in importance during the first part of UCMR 2 monitoring, EPA 
will consider an amendment that would add up to four additional 
contaminants for monitoring in a later phase of the cycle. The 
remainder of this section discusses the specific selection of 
contaminants that EPA is proposing for UCMR 2 monitoring.
    a. Health Effects Prioritization Approach. In identifying 
contaminants for monitoring under the UCMR program, potential human 
health effects are an important consideration. Therefore, after 
compiling a broad list of potential UCMR contaminants, EPA's next step 
was to develop a process to prioritize these contaminants by estimating 
their relative adverse health effects. EPA first collected existing 
health effects information, including Reference Dose (RfD), Tolerable 
Daily Intake (TDI), Acceptable Daily Intake (ADI), Cancer Unit Risk, 
Cancer Classification, and Median Lethal Dose (LD50). Using 
this information, EPA developed a screening system to rank contaminants 
into high, medium, and low relative priorities.
    In developing the relative rankings, EPA recognized two tiers of 
data for the assessment of non-cancer toxicity, based on applicability 
to human health effects: (1) RfD (and its equivalents); and (2) 
LD50. The RfD and equivalent measures such as TDI and ADI 
are doses that are expected to have no measurable health effects on the 
human population, including sensitive populations. These levels are 
based on expert judgment of the available research data. The 
LD50, on the other hand, is the result of observation of 
effects in experimental studies (i.e., the concentration at which 50% 
of experimental animals die) and has not been extrapolated for 
application to human populations. Many compounds have measured 
LD50 values, but significantly fewer have calculated RfDs. 
In prioritizing compounds for inclusion in UCMR, EPA refers to RfD (and 
equivalent data) as ``potency data'', while LD50 data are 
referred to as ``toxicity data.''
    As with the two tiers of data for non-cancer toxic effects, cancer 
information is analogously divided into two tiers. The higher tier of 
data, known as ``Unit Risk,'' represents the risk of developing cancer 
from a given drinking water concentration. The second tier of data, the 
``Cancer Classification,'' categorizes the likelihood of a compound 
contributing to the human cancer burden and is a purely qualitative 
measure. Thus, it is generally less informative than Unit Risk data.
    RfDs were typically obtained from EPA's Integrated Risk Information 
System (IRIS) or the Office of Pesticide Programs' Reregistration 
Eligibility Decisions (REDs). The ADIs were typically identified 
through the International Programme on Chemical Safety or the European 
Agency for the Evaluation of Medicinal Products Web sites. TDIs were 
identified through World Health Organization and the Netherlands 
Institute of Health Sciences sources. If an RfD or equivalent could not 
be identified, attempts were made to obtain an oral LD50 or 
other relevant information from sources such as the Hazardous 
Substances Database (HSDB) and primary literature. Cancer Unit Risk 
information was typically obtained from IRIS or REDs, while cancer 
classifications were found in IRIS, REDs, and from the International 
Agency for Research on Cancer (IARC).
    To develop a ranking for each contaminant, compounds with potency 
data were assigned values from 1 to 10 based on equations derived 
empirically from the distribution of RfDs for the compounds listed on 
IRIS. Details concerning the derivations of these equations are 
contained in a support document titled ``Estimating Potency Scores: An 
Exercise'' (USEPA, 2004h). Contaminant prioritization estimates were 
discussed at a public stakeholder meeting held on October 29, 2003; the 
estimates are contained in an additional support document titled: 
``UCMR 2: Contaminant Selection Rationale'' (USEPA, 2003e). One 
equation was derived for RfD and equivalent data, and one for cancer 
Unit Risk data. The distribution of RfD values was log-normally 
distributed, and the following equation was used to score compounds:

Non-cancer risk = 10-(rounded log10 RfD + 7)

To score compounds on a relative scale of 1 to 10, EPA examined the 
distribution of unit risks for the compounds found in the ``2002 
Drinking Water Standards and Health

[[Page 49101]]

Advisories'' (USEPA, 2002a), and used the following equation:

Cancer Risk = 10-((rounded log10 10-\4\ cancer 
risk) + 6)

Contaminants with resulting scores from each of these equations of 1-3 
were considered relatively lower priority, those with scores of 4-6 
were considered of medium relative priority, and scores of 7-10 were 
considered to be of high relative priority. In the case of compounds 
for which both cancer and non-cancer data were available, the data 
associated with the highest relative score were used for 
prioritization.

    Compounds with toxicity data were ranked by a separate system based 
on LD50, and this ranking was modified by cancer 
classification where possible. Exhibit 3 summarizes the criteria that 
were used to rank compounds by LD50.

    Exhibit 3.--Median Lethal Dose and Corresponding Toxicity Ranking
------------------------------------------------------------------------
         Relative toxicity ranking                    LD50 data
------------------------------------------------------------------------
Very High.................................  <=1 mg/kg \1\
High......................................  >1 mg/kg- <=50 mg/kg
Moderate..................................  >50 mg/kg- <=500 mg/kg
Slight....................................  >500 mg/kg- <=5 g/kg \2\
------------------------------------------------------------------------
\1\ mg/kg = milligram per kilogram.
\2\ g/kg = gram per kilogram.

    Additionally, if a chemical meeting the ``slight'' criteria was 
also noted as ``possibly carcinogenic to humans'' (Group 2B), the 
chemical was moved up one level to ``moderate.'' For example, 
2,2',4,4',5,5'-hexabromobiphenyl toxicity should be categorized as 
slight based on an identified oral LD50 in rats of 21,500 
milligrams per kilogram (mg/kg). However, because IARC categorized this 
chemical as ``possibly carcinogenic to humans,'' it now is categorized 
as moderate.
    b. Selections Based on UCMR 1 Reserved Contaminants List. One of 
EPA's priorities for UCMR 2 is to monitor for contaminants that were 
identified as priorities for monitoring during UCMR 1, but were 
``reserved'' because analytical methods were not available at the time. 
Applying these criteria, two UCMR 1 ``reserved'' contaminants are 
priorities for UCMR 2: alachlor ethane sulfonic acid (alachlor ESA) 
(and other acetanilide pesticide degradation products) and hexahydro-
1,3,5-trinitro-1,3,5-triazine (RDX), an explosive. The first is a 
contaminant group that is comprised of multiple contaminants, as 
further discussed in this section. Both alachlor ESA (and other 
degradation products of acetanilide pesticides) and RDX were included 
on UCMR 1, List 2, but because the required analytical methods were not 
available in time for UCMR 1 monitoring they were listed as 
``reserved.''
    i. Alachlor ethane sulfonic acid (ESA) and Other Degradation 
Products of Acetanilide Pesticides--List 2.
    Based on the rationale provided below, EPA is proposing that the 
following six degradation products of acetanilide pesticides and their 
parent compounds be part of the UCMR 2, List 2, Screening Survey 
monitoring:
     Acetochlor
     Acetochlor ESA
     Acetochlor OA
     Alachlor
     Alachlor ESA
     Alachlor OA
     Metolachlor
     Metolachlor ESA
     Metolachlor OA
    The proposed List 2 analytes include the ethane sulfonic acid (ESA) 
and oxanilic acid (OA) degradation products of the three highest-use 
parent acetanilide compounds: metolachlor, alachlor, and acetochlor 
(see Exhibit 4). In addition, EPA is proposing that List 2 include the 
parent compounds, acetochlor, alachlor and metolachlor, because one 
possible option for regulating these compounds and their degradates 
would be to establish maximum contaminant levels (MCLs) for the total 
of each parent plus its respective metabolites.
    There are a number of reasons why EPA has prioritized alachlor ESA 
(and other degradation products of acetanilide pesticides) for 
inclusion in UCMR 2 monitoring. This group of acetanilide degradation 
products was originally listed under the CCL 1 occurrence priorities 
and then included as part of UCMR 1, List 2 as ``reserved''; thus the 
group is a top priority for UCMR 2 monitoring. In addition, ambient 
water monitoring data indicate that occurrence of the acetanilide 
degradation products (ESA and OA) is more widespread than that of the 
parent compounds.
    Inclusion of the parent acetanilides on List 2 monitoring will 
potentially allow EPA to learn more about the extent of decomposition 
of the parent compounds, and about levels of co-occurrence of the 
parents and their degradation products. The parent acetanilides are 
widely used herbicides applied for weed control on corn, soybean, and 
other crops (see Exhibit 4). Acetochlor and metolachlor were both 
included on the final CCL 1 priority list. Acetochlor was identified as 
a CCL 1 occurrence priority, and was monitored under UCMR 1, List 1, 
Assessment Monitoring. Metolachlor and its degradation products were 
identified in the list of candidates for regulatory determination under 
the CCL 1 prioritization process. However, EPA has since determined 
that available health effects and occurrence information were 
insufficient to support a regulatory determination.
    Health effects studies have shown that chronic oral exposure to 
parent acetanilide herbicides may have effects such as increased 
salivation, decreased body weight, cellular/kidney/testicular 
pathology, enlarged liver, and anemia in animal subjects (USEPA, 
2003d). RfDs established by EPA for these parent herbicides are 0.01 
milligrams per kilograms per day (mg/kg/day) for alachlor, 0.02 mg/kg/
day for acetochlor, and 0.15 mg/kg/day for metolachlor (USEPA, 2003d). 
Based on animal studies, the carcinogenic potentials of the parent 
acetanilide herbicides in humans are estimated to be: acetochlor and 
metolachlor, ``possible carcinogen'' (59 FR 13654, March 23, 1994 
(USEPA, 1994); 61 FR 10681, March 15, 1996 (USEPA, 1996a); and USEPA, 
2003d); and alachlor, ``probable carcinogen'' (USEPA, 2004a). The NPDWR 
for alachlor includes an maximum contaminant level goal of zero (due to 
classification as a probable carcinogen) and an MCL of 0.002 milligrams 
per liter (mg/L). EPA notes that alachlor is currently regulated under 
the National Primary Drinking Water Standards. EPA is proposing the 
collection of alachlor occurrence data in UCMR 2 concurrent with the 
collection of data for the alachlor degradation products to determine 
the degree of correlation between the parent compound and degradate 
occurrence.

[[Page 49102]]



                                                Exhibit 4.--Comparison of Acetanilide Herbicides Use \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                           ~1991-1995       ~1995-1998
                                                                       ~Early 1990s     ~1992 annual     ~1997 annual      annual use       annual use
                     Compound                             Year          annual use    use (million lb  use (million lb    (million lb      (million lb
                                                       registered      (million lb      a.i.) -NCFAP    a.i.)  -NCFAP     a.i.)  -USGS     a.i.)  -USGS
                                                                     a.i.)  -EPA \2\        \3\                               \4\              \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Metolachlor.......................................            1976               59             59.4             67.3             57.9             66.9
                                                                        (1987-1993)
Alachlor..........................................            1969        29.3-44.6             51.6             15.2             25.7             15.1
                                                                        (1993-1995)
Acetochlor........................................            1994               --               --             32.6             23.8             32.6
Propachlor........................................            1964              2.1              4.3              0.9              3.9              0.9
                                                                        (1987-1996)
Dimethenamid......................................            1993               --               --              6.0              2.6              6.0
Flufenacet........................................            1998               --               --               --               --              --
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ ``--'' = substance not in use; a.i. = active ingredient.
\2\ EPA: http://cfpub.epa.gov/oppref/rereg/status.cfm?show=rereg.
\3\ National Center for Food and Agricultural Policy (NCFAP): http://www.ncfap.org/.
\4\ United States Geological Survey (USGS), national maps: http://ca.water.usgs.gov/pnsp/.
Note: Based on use amounts, EPA is proposing to monitor for the ESA and OA degradates of the three highest-use parent compounds: acetochlor, alachlor,
  and metolachlor. In addition, EPA is proposing to monitor for acetochlor, alachlor, and metolachlor.

    ii. Explosives--List 1.
    Based on the rationale provided below, EPA is proposing that the 
following three explosives compounds be part of the UCMR 2, List 1, 
Assessment Monitoring:
     Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)
     2,4,6-trinitrotoluene (TNT)
     1,3-dinitrobenzene
    RDX was a CCL 1 occurrence priority and was included on UCMR 1, 
List 2 as ``reserved,'' because analytical methods were not available 
in time for rule implementation. EPA has since developed a method for 
determining explosives in drinking water, thus allowing RDX to be 
included under UCMR 2 monitoring. RDX is absorbed by oral, dermal, and 
inhalation routes, and has been documented to cause central nervous 
system effects such as seizures, disorientation, nausea, restlessness, 
and lethargy. In addition, temporary anemia and leukocytosis after 
ingestion of RDX has been observed (ATSDR, 1995b). EPA has derived a 
chronic oral RfD for RDX of 0.0003 mg/kg/day, based on prostate 
inflammation observed in rats in a two-year feeding study (USEPA, 
2003d), and has classified RDX as a possible human carcinogen (Group 
C), based on adenomas and carcinomas in female mice (USEPA, 2003d).
    The ``explosives'' method can also be used to measure 
concentrations of at least 13 other contaminants in the same compound 
class (see Exhibit 5). A few that can be detected by this method were 
already monitored under UCMR 1 (nitrobenzene, 2,4-dinitrotoluene, and 
2,6-dinitrotoluene). Of the remaining contaminants analyzed with the 
explosives method, the two with the highest relative health risk 
rankings are 2,4,6-trinitrotoluene (TNT) (possible carcinogen) and 1,3-
dinitrobenzene (high relative health risk ranking). TNT and 1,3-
dinitrobenzene were also identified during the CCL 1 development 
process on the working group's initial list of chemical contaminants 
considered during the development of the draft CCL (62 FR 52194 at 
52201, October 6, 1997 (USEPA, 1997)).
    TNT has been detected in surface and ground water samples that were 
collected near munitions facilities (ATSDR, 1995c). TNT typically co-
occurs with RDX (Burrows, 1982). EPA has classified TNT as a possible 
human carcinogen (Group C) based on urinary bladder papilloma and 
carcinoma observed in female rats and activity observed in Salmonella, 
with and without metabolic activation (USEPA, 2003d). Based on TNT's 
co-occurrence with RDX and its possible carcinogenicity, EPA is 
proposing to include TNT for monitoring under UCMR 2.
    1,3-dinitrobenzene is the only one of the explosive contaminants 
considered for UCMR 2 to have been assigned a ``high'' relative health 
risk ranking. The major clinical manifestations of oral exposure to 
1,3-dinitrobenzene are hematologic, neurologic, endocrine, and 
reproductive (ATSDR, 1995a). EPA has derived a chronic oral RfD for 
this compound of 0.0001 mg/kg/day, based on increased weight of the 
spleen (USEPA, 2003d). EPA believes that a likely route of exposure to 
this compound is ingestion of contaminated drinking water (ATSDR, 
1995a). Though no nationwide survey of occurrence has been conducted, 
local water and soil studies provide some indication of 1,3-
dinitrobenzene occurrence in water. This compound has been detected in 
water and soil at some Army ammunition plants, including detection in 
ground water samples collected at an ammunition plant in Louisiana at 
concentrations ranging from 1.2 to 195 micrograms per liter ([mu]g/L) 
(ATSDR, 1995a). It has also been found in 12 of the 1,397 hazardous 
waste sites on the National Priorities List; however, the total number 
of sites tested for 1,3-dinitrobenzene is unknown (ATSDR, 1995a). In a 
survey of ground water at 32 military installations, Walsh and 
colleagues (USEPA, 1999a) detected 1,3-dinitrobenzene in 13 percent of 
the 812 samples analyzed, with maximum concentrations of 8.7 [mu]g/L 
and a median concentration of 0.78 [mu]g/L. As the most toxic of the 
remaining explosives, EPA believes that 1,3-dinitrobenzene should be 
included for monitoring under UCMR 2.

    Exhibit 5.--Analytes Included in the Explosives Method (EPA 529)
------------------------------------------------------------------------
                                                        Relative health
            Status                     Analyte              rank \1\
------------------------------------------------------------------------
To be monitored under UCMR 2,   hexahydro-1,3,5-       M(C)
 List 1.                         trinitro-1,3,5-       M(C)
                                 triazine (RDX).       H
                                2,4,6-trinitrotoluene
                                 (TNT).
                                1,3-dinitrobenzene...

[[Page 49103]]

 
Not Listed on CCL 1 and Not     1,3,5-trinitrobenzene  M
 included on UCMR 2.            2,4,6-                 M
                                 trinitrophenylmethyl  L(S)
                                 nitramine (Tetryl).   L(S)
                                2-amino-4,6-           na
                                 dinitrotoluene.       M(M)
                                2-nitrotoluene.......  L(S)
                                3,5-dinitroaniline...  L(S)
                                3-nitrotoluene.......
                                4-amino-2,6-
                                 dinitrotoluene.
                                4-nitrotoluene.......
Listed on CCL 1 and Monitored   2,4-dinitrotoluene...  M
 under UCMR 1.                  2,6-dinitrotoluene...  M
                                nitrobenzene.........  M
------------------------------------------------------------------------
\1\ Relative Health Effects Rankings include: H = high priority based on
  potency data (RfD or equivalent); M = medium priority based on potency
  data (RfD or equivalent); M(C) = medium priority based on potency data
  (cancer unit risk); M(M) = medium priority based on toxicity data
  (contaminants with Moderate (M) toxicity are contained in this
  category); L(S) = low priority based on toxicity data (contaminants
  with Slight (S) toxicity are contained in this category); (na) = not
  available.

    c. Selections from UCMR 1 Contaminants List. Perchlorate, the salts 
of which have a number of industrial applications, is primarily used in 
the form of ammonium perchlorate, an oxidizer in solid fuels that are 
used to power rockets, missiles, and fireworks. In 1997, a method was 
developed which greatly lowered the method reporting limit (MRL) for 
perchlorate from approximately 400 [mu]g/L, down to 4 [mu]g/L. 
Subsequent monitoring found perchlorate in ground water and drinking 
water at and above this level. Perchlorate was listed on EPA's CCL 1 
out of concern for its occurrence and possible health effects and was 
monitored under UCMR 1 Assessment Monitoring using Method 314.0 (USEPA, 
1999e), with a MRL of 4 [mu]g/L.
    EPA has improved the measurement capabilities of the perchlorate 
methods. Recently developed methods (EPA Method 314.1 (USEPA, 2004b); 
EPA Method 331.0 (USEPA, 2004c); and EPA Method 332.0 (USEPA, 2004d)) 
would allow collection of occurrence data with a substantially lower 
reporting level than that specified during UCMR 1. In addition, since 
publication of Method 314.0, new instrumentation has been made 
commercially available that can, using this method, achieve the MRL of 
0.57 [mu]g/L while meeting all of the quality control criteria of the 
method. Since Method 314.0 permits flexibility in the eluent, 
chromatographic column, and suppressor that are used, this new 
instrumentation is allowed within the scope of the method. In this 
notice, EPA will refer to Method 314.0 using this new instrumentation, 
which can achieve the lower MRL as ``Method 314.0 enhanced.'' EPA 
estimates that the average cost per sample for the new methods will be 
about $150, compared to $75 per sample using the original Method 314.0.
    The National Academy of Sciences (NAS) has recently completed a 
review of available perchlorate health effects research. Perchlorate 
can affect thyroid function because it is an ion that competitively 
inhibits the transport of iodide into the thyroid. EPA has adopted the 
NAS recommended reference dose of 0.0007 mg/kg per day, which 
translates into a drinking water concentration of 24.5 [mu]g/L, 
assuming a 70 kg body weight and 2 liters per day consumption. This 
assumes, however, that 100% of exposure comes from drinking water. An 
important step for EPA in considering whether to regulate perchlorate 
in drinking water is to determine what portion of perchlorate exposure 
may come from food and other sources and what portion from drinking 
water (referred to as relative source contribution or RSC). A higher 
exposure from food would mean a lower exposure from drinking water that 
would still be consistent with the NAS recommended reference dose.
    EPA is considering whether to collect additional data on drinking 
water occurrence for perchlorate and if so, what method(s) and MRL 
should be required. The Agency already has substantial occurrence data 
for perchlorate from UCMR 1 using the original Method 314.0, which 
allowed for measurement of perchlorate at concentrations down to 4 
[mu]g/L. However, to inform future decisions regarding perchlorate, EPA 
sees advantages to gathering additional data on perchlorate using the 
newer methods. This additional information would provide a more 
complete understanding of perchlorate's occurrence in drinking water. 
For large systems, the new monitoring data would supplement data 
already collected by these systems under UCMR 1, while for small 
systems, a different random sample would be monitored. Further, 
additional data at lower reporting levels could inform EPA's cost 
estimates for a potential regulation by identifying drinking water 
systems that may want, as a practical matter, to target a somewhat 
lower level than the MCL in their control strategies. Finally, EPA 
believes the new methods are more reliable and respond to comments 
about the potential for false positives in the original Method 314.0. 
At the same time, EPA recognizes that there are costs associated with 
this additional monitoring, most of which would be incurred by drinking 
water utilities and their customers. The cost of an additional round of 
monitoring using the original method 314.0, with an MRL of 4 [mu]g/L, 
would have been about half of the cost associated with the new methods 
and lower MRL. EPA estimates the total cost for a second round of 
perchlorate monitoring using the new methods to be $4.4 million over 
five years, of which about $4 million would be incurred by large 
drinking water utilities (an average of $1,200 per utility serving 
10,000 persons or more), and $434,000 would be paid by EPA to analyze 
samples for small systems. EPA requests comment on its proposal to 
include perchlorate on the UCMR 2 list and on the appropriate methods 
and reporting level.
    d. Selection of Emerging Contaminants. Ongoing research has 
identified other emerging contaminants that EPA believes are important 
to include on the UCMR 2 Contaminant List.
    i. Nitrosamines--List 2.
    EPA is proposing to include the following six nitrosamines on the 
UCMR 2, List 2, Screening Survey:
     N-nitroso-diethylamine (NDEA)
     N-nitroso-dimethylamine (NDMA)
     N-nitroso-di-n-butylamine (NDBA)
     N-nitroso-di-n-propylamine (NDPA)

[[Page 49104]]

     N-nitroso-methylethylamine (NMEA)
     N-nitroso-pyrrolidine (NPYR)
    These six compounds are all considered by EPA to be probable human 
carcinogens, and have been assigned high relative health effects 
rankings (USEPA, 2003d). Animal studies provide evidence that many 
nitrosamines, including all of those being proposed for UCMR 2, target 
the liver when ingested orally. Nitrosamines also produce carcinogenic 
effects in the esophagus, lung, nasal cavity, stomach, and elsewhere 
when administered to animal subjects in drinking water; and many 
nitrosamines target the liver when ingested orally (USEPA, 2003d). 
Nitrosamines are produced in small amounts for research purposes, and 
can form as intermediates and byproducts in chemical synthesis and the 
manufacture of rubber, leather, and plastics. Four of the six proposed 
nitrosamines (all except N-nitroso-methylethylamine and N-nitroso-
pyrrolidine) are listed on the Toxics Release Inventory (TRI),\2\ which 
requires reporting of releases to the environment and other waste 
management data. Nitrosamines can also form spontaneously in the 
environment by the reaction of precursor amines with nitrosating agents 
(nitrate and related compounds), or by the action of nitrate-reducing 
bacteria. Common foods such as bacon and malt beverages can contain 
nitrosamines, and there is evidence that nitrosamines can form in the 
upper gastrointestinal tract (ATSDR, 1989). One nitrosamine, N-nitroso-
dimethylamine (NDMA), has been shown to form in chlorinated or 
chloraminated water as a disinfection byproduct (DBP) (Choi et al., 
2002; Choi and Valentine, 2002a and 2002b; Mitch and Sedlak, 2002).
---------------------------------------------------------------------------

    \2\ The Toxics Release Inventory (TRI) is a publicly available 
EPA database that contains information on toxic chemical releases 
and other waste management activities reported annually by certain 
covered industry groups as well as Federal facilities. This 
inventory was established under the Emergency Planning and Community 
Right-to-Know Act of 1986 and expanded by the Pollution Prevention 
Act of 1990. Generally, reporting is required for facilities in 
covered industries with more than 10 full-time employees that 
annually manufacture or process more than 25,000 pounds, or use more 
than 10,000 pounds of a toxic chemical. More information is 
available at the TRI Program Web site at: http://www.epa.gov/tri.
---------------------------------------------------------------------------

    No nationwide data are available on nitrosamine occurrence in 
United States waters. However, other studies give an indication of 
likely occurrence. Since 1998, a number of NDMA detections have been 
reported in California ground water (CAEPA, 2002) and finished drinking 
water (CADHS, 2002) above the State's action level of 0.01 [mu]g/L. The 
American Water Works Association Research Foundation recently 
collaborated with the Water Environment Research Foundation to fund a 
study on NDMA occurrence and behavior in raw, treated, and recycled 
water; however, the final report is not yet available.
    Given evidence of the toxic nature of nitrosamines, and their 
potential occurrence in the environment (particularly NDMA in drinking 
water as a DBP), EPA proposes to include these six contaminants on the 
UCMR 2 list to learn more about their occurrence in drinking water.
    ii. Others Identified in CCL 1 Process and Recent Reviews of 
Information on Emerging Contaminants--List 1.
    The following additional contaminants are proposed for UCMR 2, List 
1, Assessment Monitoring based on evaluation of CCL 1 lists and methods 
research.
     Dimethoate
     Terbufos sulfone
     Five flame retardants

Four polybrominated diphenyl ethers:
    2,2',4,4'-tetrabromodiphenyl ether (BDE-47)
    2,2',4,4',5-pentabromodiphenyl ether (BDE-99)
    2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153)
    2,2',4,4',6-pentabromodiphenyl ether (BDE-100)
One polybrominated biphenyl:
    2,2',4,4',5,5'-hexabromobiphenyl (245-HBB)

    There are a variety of reasons these contaminants are being 
proposed for monitoring under UCMR 2. Terbufos sulfone was identified 
through the CCL 1 development process as a deferred pesticide. 
Dimethoate and the flame retardants are other contaminants that can be 
measured by the same analytical method that is proposed for terbufos 
sulfone. Terbufos sulfone and dimethoate have both been assigned 
``high'' relative health effects rankings. Flame retardants are being 
proposed by EPA for UCMR monitoring because of recent concern that 
these have become widely occurring environmental contaminants (Darnerud 
et al., 2001).
    Although little is known regarding the health effects of terbufos 
sulfone, EPA has established an RfD of 0.00005 mg/kg/day for the parent 
compound, terbufos, based on a no observable adverse effect level for 
plasma cholinesterase inhibition (USEPA, 1999b). Terbufos was monitored 
under UCMR 1. Similar to the acetanilide degradates, however, EPA is 
concerned that terbufos sulfone will be found more commonly in the 
environment than its parent compound, based on the rapid decomposition 
of the parent compound. Such rapid decomposition combined with concern 
regarding the health effects of the parent compound terbufos justify 
determining the occurrence of terbufos sulfone in drinking water.
    The method EPA proposes for the analysis of terbufos sulfone can 
measure many other contaminants (over 40). However, EPA used relative 
health effects information to identify the highest priorities and to 
comply with the statutory limit of 30 contaminants per UCMR monitoring 
cycle. Of the remaining compounds that could be measured using gas 
chromatography/mass spectrometry (GC/MS), the technology used in Method 
527, dimethoate is being proposed for UCMR 2 monitoring because it 
received a ``high'' ranking in EPA's health effects screening (USEPA, 
2004h). Dimethoate is a TRI chemical that is produced for use on cotton 
and other field crops, orchard crops, vegetable crops, in forestry, and 
residential uses (USEPA, 1999f).
    Dimethoate is rapidly absorbed, metabolized, and eliminated in rats 
by oral or intravenous routes of administration (USEPA, 1999d). This 
compound is a cholinesterase inhibitor and exerts its major toxic 
effects through overstimulation of the nervous system (USEPA, 2003a). 
Health effects include headache, weakness, coma, and death from 
respiratory failure (HSDB, 1986). Dimethoate has been classified as a 
``possible human carcinogen'' and EPA has established an RfD for this 
compound of 0.0002 mg/kg/day (USEPA, 2003d). No national data is 
available on the occurrence of dimethoate in waters of the United 
States; however, two local studies provide an indication of limited 
occurrence (USEPA, 1999f).
    Synthetic flame retardants are among the other contaminants that 
are measured by EPA Method 527. Flame retardants, such as 
polybrominated diphenyl ethers (PBDEs) and polybrominated biphenyls 
(PBBs), are added to plastics used in a variety of consumer products 
such as computer monitors, televisions, textiles, and plastic foams. 
Production of PBBs ended in 1976 in the United States following an 
incident of significant agricultural contamination in 1973, but PBDEs 
are still produced and used in the United States. Flame retardants have 
been measured at low levels in air, sediments, animals, and food and 
are believed to be widely occurring in the environment (Darnerud et 
al., 2001). Recent data also indicate that total levels of flame 
retardants are rapidly

[[Page 49105]]

increasing and that most people are exposed to low levels of these 
contaminants (Hites, 2004). Findings from animal studies suggest 
thyroid and liver effects, as well as possible reduced immune system 
function and neurobehavioral alteration (ATSDR, 2002).
3. Other Considerations in Selecting Contaminants
    EPA has identified nine analytical methods and 26 priority 
contaminants for UCMR 2 monitoring. EPA considered many more 
contaminants and methods for UCMR 2. Some of these contaminants were 
given strong consideration but were not included as part of the 
proposed UCMR 2, as discussed in the following section.
    a. Triazine Chlorodegradates and Parent Compounds. While they are 
not part of today's proposal, EPA invites comments on the possibility 
of UCMR 2 monitoring for three triazine chlorodegradates and three of 
their parent compounds, as follows:
     Desethylatrazine (DEA)
     Desisopropylatrazine (DIA)
     Diaminochlorotriazine (DACT) \3\
     Atrazine
     Simazine
     Propazine
---------------------------------------------------------------------------

    \3\ Another commonly used name for DACT is 
desthyldesisopropylatrazine.
---------------------------------------------------------------------------

    EPA is interested in these chlorodegradates and three parent 
compounds because the Agency is conducting a cumulative risk assessment 
for the chlorodegradates as a group with atrazine, simazine and 
propazine. The ``triazines and degradation products of triazines'' are 
also CCL 1 contaminants.
    Atrazine and simazine are regulated contaminants with MCLs of 3 
[mu]g/L and 4 [mu]g/L, respectively. Propazine was a cancelled 
pesticide based on its contamination of ground water but was 
reintroduced for greenhouse uses only (it is now used on container 
grown ornamentals in greenhouses); however, EPA is currently evaluating 
a proposal to use propazine for the control of broadleaf weeds and 
annual grasses in sorghum, a use previously listed on labels, but 
voluntarily removed prior to 1990. Propazine was identified through the 
CCL 1 development process as a deferred pesticide. A fourth triazine, 
cyanazine, is not being addressed since its production and use were 
phased out between 1996 and 2002.
    Atrazine, simazine and propazine metabolize into various 
chlorodegradation products of which Desethylatrazine (DEA), 
Desisopropylatrazine (DIA), and Diaminochlorotriazine (DACT) are the 
most significant. Atrazine forms all three of these chlorodegradates; 
whereas, simazine, a diethyl analogue of atrazine, degrades to DIA and 
DACT, and propazine, a diisopropyl analogue of atrazine, degrades to 
DACT and DEA (Scribner et al., 2000). In addition, ambient water 
monitoring data indicate that concentrations of these chlorodegradates 
in water may be equal to, or even exceed, concentrations of atrazine 
(and other parent compounds) (Scribner et al., 2000). While atrazine 
and simazine are already regulated under the National Primary Drinking 
Water Standards, EPA is considering UCMR monitoring for these parent 
compounds concurrent with the collection of UCMR data for their 
degradation products to determine the degree of correlation between the 
occurrence of the parents and their degradation products.
    EPA is currently developing a liquid chromatography/tandem mass 
spectrometry (LC/MS/MS) method to analyze the parent triazines and 
these chlorodegradates and expects that method to be available within 
the next year. Depending on method development progress, EPA's further 
assessment of the relative health effects of triazine degradates, and 
comments received pursuant to today's proposed regulation, EPA may 
consider adding triazines and degradates to the Screening Survey for 
UCMR 2. Because only 30 analytes can be monitored during any one cycle 
of the UCMR program, EPA recognizes that the addition of the triazines 
and degradates to the Screening Survey may require the elimination of 
other contaminants from UCMR 2. Contaminants that EPA is considering in 
this regard may include one or more of the acetanilide pesticides or 
degradation products (see section III.A.2.b.i), which are also measured 
using an LC/MS/MS method. EPA invites comments on whether the 
concurrent use of two similar methods may strain laboratory capacity.
    b. Other Contaminants Considered. EPA had originally identified 
over 200 contaminants as potential UCMR 2 priorities. Many were 
eliminated based on specific criteria, as discussed in section III.A.2 
of this action (including the requirements that pesticides must be 
registered, reference standards must be available, and the analytical 
method must be available to include in this proposed action). Those 
eliminated or deferred due to other considerations are worthy of 
further mention because of particular public interest. These 
contaminants, and the reasons for their exclusion from today's proposed 
action, include:
     Aeromonas: The UCMR 1 Screening Survey for Aeromonas 
indicates that it warrants further evaluation. Data analyzed thus far 
have identified Aeromonas at the genus level. Identification and 
analysis of pathogenic strains for some of the small system samples is 
underway but have not been completed as of the publication of this 
proposed action. EPA believes that it is premature to propose 
additional monitoring for Aeromonas. The evaluation of the speciation 
of the isolates collected during UCMR 1, and the development of a more 
routine and affordable species-specific method will support future 
monitoring, if deemed appropriate.
     Cyanotoxins: While extensive analytical methods 
development was conducted for one class of cyanobacteria toxins, 
microcystins, in preparation for UCMR 2, adequate accuracy in surface 
waters with total organic carbon levels of 2 mg/L and higher has not 
yet been demonstrated. Two other cyanotoxins--anatoxin A, and 
cylindrospermopsin--were included in the initial method development. 
However, these were not compatible with the microcystin method being 
developed, and other analytical methods will not be available in time 
for UCMR 2 monitoring. Therefore, none of the cyanobacteria toxins are 
being proposed for monitoring at this time. However, further analytical 
methods development is continuing.
     Diuron: EPA considered whether Diuron would be a good 
candidate to include in UCMR 2 Assessment Monitoring. Interim 
monitoring results from the UCMR 1 Screening Survey have shown only one 
detection of Diuron. Because this suggests very low occurrence in 
drinking water, and because other contaminants are of greater relative 
health effects concern, Diuron was not established as a priority 
contaminant for UCMR 2 monitoring.
     Ethylene thiourea: While extensive analytical methods 
development was conducted for ethylene thiourea in preparation for UCMR 
2, reproducible recoveries have not yet been demonstrated. Therefore, 
ethylene thiourea is not being proposed for monitoring at this time. 
However, further analytical methods development is continuing.
     Mirex and TBBPA: Mirex was considered for UCMR 2 
monitoring and was found to have a ``high'' relative health effects 
ranking. Though it can be measured using the GC/MS method, Mirex has 
not been used or produced in the United States since 1978. For this

[[Page 49106]]

reason, EPA has not included Mirex on the list of UCMR 2 priorities. In 
addition, tetrabromobisphenol A (TBBPA), a brominated flame retardant, 
was initially considered for inclusion on the list of contaminants to 
be measured using GC/MS, EPA Method 527. However, TBBPA was found to be 
incompatible with this method, and is therefore not included on the 
list of UCMR 2 priorities.

B. What Analytical Methods Will Be Used for Monitoring?

    The analytical methods that are being proposed for use in UCMR 2 
and the contaminants that they measure are listed in Exhibit 6. EPA has 
conducted both literature searches, as well as searches of available 
consensus method organizations' publications for additional analytical 
methods that could be used to support this monitoring. No such 
additional methods were identified that meet the requirements of this 
proposed action. All of the analytical methods proposed use either mass 
spectrometry or tandem mass spectrometry (i.e., MS/MS) for the 
detection of the analytes, with the exception of EPA Methods 314.0 
enhanced and 314.1 (USEPA, 1999e and USEPA, 2004b, respectively).
    EPA is proposing that all positive occurrences of perchlorate 
(i.e., those at or above the MRL of 0.57 [mu]g/L), determined using the 
Methods 314.0 enhanced or 314.1, must be confirmed through the use of a 
second chromatographic column, as detailed in Method 314.1, or by MS or 
MS/MS, using EPA Methods 331.0 or 332.0 (USEPA, 2004c and USEPA, 2004d, 
respectively). EPA requests comment on the level at which positive 
occurrences of perchlorate must be confirmed.
    By design of the UCMR program, UCMR contaminants measured by 
analytical techniques that are commonly available are assigned to List 
1, Assessment Monitoring (EPA Methods 314.0 enhanced, 314.1, 331.0, 
332.0, 527, and 529). While most of these are newly developed 
analytical methods, the techniques they employ are in common use by 
drinking water laboratories. These methods are assigned to Assessment 
Monitoring because this is the largest component of UCMR, with 
monitoring conducted by a sample of 800 systems serving 10,000 or fewer 
people, and all systems serving more than 10,000 people (approximately 
3,200 systems).
    UCMR contaminants that are measured by analytical methods that have 
been recently developed and use techniques that are not commonly used 
in drinking water analyses are assigned to the List 2, Screening 
Survey. These less common methods are generally more appropriate for 
the Screening Survey because fewer laboratories will be capable of 
conducting such analyses, and the smaller scale monitoring under the 
Screening Survey should reduce potential laboratory capacity issues. 
However, in order to monitor for the parent compounds of the 
acetanilide degradates, Method 525.2, which is commonly used for 
regulated monitoring, is also being included for List 2 monitoring. 
During the Screening Survey, a sample of 800 systems serving 100,000 or 
fewer people and all (approximately 320) systems serving more than 
100,000 people would monitor. Exhibit 6, summarizes the UCMR 2 methods 
and associated contaminants.

      Exhibit 6.--Analytical Methods Proposed for UCMR 2 Monitoring
------------------------------------------------------------------------
    Analytical method \1\          Contaminant           UCMR 2 List
------------------------------------------------------------------------
EPA Method 314.0 enhanced     Perchlorate.........  List 1, Assessment
 (IC/Conductivity).                                  Monitoring: 1
                                                     contaminant.
EPA Method 314.1 (IC/
 Conductivity)
EPA Method 331.0 (LC/MS or
 LC/MS/MS)
EPA Method 332.0 (IC/MS or
 IC/MS/MS)
EPA Method 527 (SPE/GC/MS)..  2,2',4,4'-
                               tetrabromodiphenyl
                               ether (BDE-47).
                              2,2',4,4',5-
                               pentabromodiphenyl
                               ether (BDE-99).
                              2,2',4,4',5,5'-
                               hexabromobiphenyl
                               (245-HBB).
                              ....................  List 1, Assessment
                                                     Monitoring: 7
                                                     contaminants.
                              2,2',4,4',5,5'-
                               hexabromodiphenyl
                               ether (BDE-153).
                              2,2',4,4',6-
                               pentabromodiphenyl
                               ether (BDE-100).
                              Dimethoate..........
                              Terbufos sulfone....
EPA Method 529 (SPE/GC/MS)..  1,3-dinitrobenzene..  List 1, Assessment
                              2,4,6-                 Monitoring: 3
                               trinitrotoluene       contaminants.
                               (TNT).
                              Hexahydro-1,3,5-
                               trinitro-1,3,5-
                               triazine (RDX).
EPA Method 521 (SPE/GC/CI/MS/ N-nitroso-            List 2, Screening
 MS).                          diethylamine (NDEA).  Survey: 6
                              N-nitroso-             contaminants.
                               dimethylamine
                               (NDMA).
                              N-nitroso-di-n-
                               butylamine (NDBA).
                              N-nitroso-di-n-
                               propylamine (NDPA).
                              N-nitroso-
                               methylethylamine
                               (NMEA).
                              N-nitroso-
                               pyrrolidine (NPYR).
EPA Method 535 (SPE/HPLC/MS/  Acetochlor ESA......  List 2, Screening
 MS).                         Acetochlor OA.......   Survey: 6
                              Alachlor ESA........   contaminants.
                              Alachlor OA.........
                              Metolachlor ESA.....
                              Metolachlor OA......
EPA Method 525.2 (SPE/GC/MS)  Acetochlor..........  List 2, Screening
                              Alachlor............   Survey: 3
                              Metolachlor.........   contaminants.

[[Page 49107]]

 
Total of 26 UCMR 2
 contaminants
------------------------------------------------------------------------
\1\ EPA Method 314.0: Determination of Perchlorate in Drinking Water
  Using Ion Chromatography (USEPA, 1999e). Note: Since Method 314.0 was
  published in 1999 to support UCMR 1 monitoring at an MRL of 4.0 [mu]g/
  L, new instrumentation has been made commercially available from
  Metrohm Peak that can, using this method, achieve the MRL of 0.57
  [mu]g/L as called for by this proposed regulation, while meeting all
  of the quality control criteria of the method. Because enhanced Method
  314.0 permits flexibility in the eluent, chromatographic column, and
  suppressor that are used, this new instrumentation would be permitted
  within the scope of the original method. Therefore, enhanced Method
  314.0 is being proposed for use in this regulation.
EPA Method 314.1: Determination of Perchlorate in Drinking Water Using
  Inline Column Concentration/Matrix Elimination Ion Chromatography with
  Suppressed Conductivity Detection (USEPA, 2004b).
EPA Method 331.0: Determination of Perchlorate in Drinking Water by
  Liquid Chromatography Electrospray Ionization Mass Spectrometry
  (USEPA, 2004c)
EPA Method 332.0: Determination of Perchlorate in Drinking Water Using
  Ion Chromatography with Suppressed Conductivity and Electrospray
  Ionization Mass Spectrometry (USEPA, 2004d).
EPA Method 521: Determination of Nitrosamines in Drinking Water by Solid
  Phase Extraction and Capillary Column Gas Chromatography with Large
  Volume Injection and Chemical Ionization Tandem Mass Spectrometry (MS/
  MS) (USEPA, 2004e).
EPA Method 525.2: Determination of Organic Compounds in Drinking Water
  by Liquid-Solid Extraction and Capillary Column Gas Chromatography/
  Mass Spectrometry (USEPA, 1995).
EPA Method 527: Determination of Selected Pesticides and Flame
  Retardants in Drinking Water by Solid Phase Extraction and Capillary
  Column Gas Chromatography/Mass Spectrometry (GC/MS) (USEPA, 2004f).
EPA Method 529: Determination of Explosives and Related Compounds in
  Drinking Water by Solid Phase Extraction and Capillary Column Gas
  Chromatography/Mass Spectrometry (GC/MS) (USEPA, 2003c).
EPA Method 535, Revision 1.1: Measurement of Chloroacetanilide and Other
  Acetamide Herbicide Degradates in Drinking Water by Solid Phase
  Extraction and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/
  MS) (USEPA, 2004g).

C. How Were These Analytical Methods Developed?

    EPA developed the proposed analytical methods at two laboratories 
in Cincinnati, Ohio: The Office of Water, Office of Ground Water and 
Drinking Water's Technical Support Center and the Office of Research 
and Development, National Exposure Research Laboratory's Chemical 
Exposure Research Branch. Additional methods development support was 
provided by: The Dionex Corporation, Sunnyvale, California; Metrohm 
Peak, Houston, Texas; Office of Research and Development's Ground Water 
and Ecosystems Restoration Division, Ada, Oklahoma; and EPA's Region 1, 
New England Laboratory, Chelmsford, Massachusetts.
    Extensive method testing was performed for each of the analytical 
methods developed for this proposed action. Each step of each method 
was tested for robustness and to evaluate the amount of user 
flexibility that could be permitted for that step. Additional details 
concerning this testing, beyond that included in each method, are 
contained in methods research reports. These reports are available for 
each newly developed method being proposed in the docket for this 
action. However, no such report is available for Method 314.0, which 
was developed for UCMR 1, or for Method 525.2, which was developed in 
1995. Wherever feasible, EPA permitted the maximum user flexibility 
commensurate with maintaining data quality. In addition, each method 
was tested in a second or, for some methods, a third laboratory. These 
second and third laboratory studies were designed to test the precision 
and accuracy of each method in reagent water and in different drinking 
water matrices, as well as the ease of use of the method and the 
clarity of the written instructions of the method. Reports containing 
the data developed during these second and third laboratory studies are 
also available in reports included in the docket for this action for 
each newly developed method being proposed. Similar data was generated 
in to support the proposed action of Method 314.0. These data are also 
included in the docket for review.
    The methods developed for UCMR 2 analyses were peer reviewed in 
accordance with the Agency's peer review guidelines detailed in the 
``Science Policy Council Handbook, Peer Review'' (USEPA, 2000b). 
Methods 314.0 and 525.2, which were developed prior to 2000, were peer 
reviewed using similar criteria.

D. How Were Minimum Reporting Levels Determined?

    Minimum Reporting Levels (MRLs) represent an estimate of the lowest 
concentration of a compound that can be quantitatively measured by a 
group of experienced drinking water laboratories. EPA is proposing that 
all laboratories providing UCMR 2 analysis be required to demonstrate 
their ability to measure each compound at the MRL proposed for that 
compound in Sec.  141.40(a)(3) of today's action. EPA has developed a 
protocol for developing MRLs based on Lowest Concentration MRLs 
(LCMRLs) that were determined by each laboratory that developed or 
subsequently tested the methods listed in today's action. LCMRLs 
represent the lowest concentration of a compound that can be 
quantitatively determined in each individual laboratory. EPA invites 
comments on the LCMRL/MRL approach and notes that in a related action, 
EPA's Office of Water is about to begin an evaluation of a wide range 
of detection and quantitation approaches under the Federal Advisory 
Committee Act (FACA) process. EPA expects to consider the comments and 
feedback from this FACA process to the extent possible in the 
development of the UCMR 2 final rule.
    MRLs have previously been determined by analytical laboratories 
using expert professional judgement, but standard criteria for MRL 
determination have not been established. In both the Information 
Collection Rule (61 FR 24354, May 14, 1996 (USEPA, 1996b)) and UCMR 1, 
EPA specified MRLs and a requirement for recovery at the MRL so that 
data quality was documented daily. In the interest of greater 
consistency, EPA has developed a statistical protocol for single-
laboratory determinations of LCMRLs using linear regression and 
prediction intervals. This approach, described in detail in the report 
titled ``Statistical Protocol for the Determination of the Single-
Laboratory Lowest Concentration Minimum Reporting Level (LCMRL) and 
Validation of the Minimum Reporting Level (MRL)'' (USEPA, 2004j), has 
been evaluated through expert peer review conducted in accordance with 
the Agency's formal peer review process and through the performance of 
a pilot-scale interlaboratory study. The

[[Page 49108]]

proposed protocol is available to the public, and can be found at: 
http://www.epa.gov/safewater/methods/sourcalt.html.
    Details of this pilot-scale interlaboratory study are contained in 
a report titled ``Evaluation of the Lowest Concentration Minimum 
Reporting Level (LCMRL) and the Minimum Reporting Level (MRL) Primary 
Analyte Analysis'' (USEPA, 2004i). An evaluation of the procedures used 
in this proposed action, and other tested procedures to determine MRLs 
from LCMRLs, are detailed in Chapter 4 of the report. The guidelines 
and procedures for using LCMRLs in establishing MRLs for UCMR 2 are 
described later in this section.
    As proposed, the MRL would be the lowest analyte concentration that 
meets Data Quality Objectives (DQOs) as presented in Sec.  141.40(a)(5) 
of today's proposed rule, and represents the lowest concentration for 
which future recovery is predicted to fall, with high confidence (99 
percent), between 50 percent and 150 percent. MRLs would be applicable 
to all laboratories that perform the analysis of drinking water samples 
as part of UCMR 2. All UCMR 2 laboratories would be required to 
validate their performance at or below the MRLs before initiating any 
analyses. This proposal does not require that measurements observed at 
concentrations below the MRL be reported. In other programs, such 
reporting may be appropriate. The appropriateness of reporting 
measurements below the MRL, is generally dependent upon the objectives 
of a study and is not addressed in this proposed action.
    To determine the MRLs listed in today's action, each laboratory 
that conducted the primary analytical method development, or second or 
third laboratory studies, determined LCMRLs as detailed in the 
statistical protocol (USEPA, 2004g). The mean of these LCMRL values was 
calculated for each analyte. In cases where data from three or more 
laboratories were available, three times the standard deviation of the 
LCMRLs was added to the mean of the LCMRLs, to establish the MRL. In 
cases where data from two laboratories were available, three times the 
difference of the LCMRLs was added to the mean of the LCMRLs. In 
statistical theory (Chebyshev's Inequality), three standard deviations 
around the mean incorporates the vast majority (at least 88.9 percent) 
of the data points. In the case where there are only two laboratories, 
the difference serves as a surrogate for the standard deviation due to 
the uncertainty in the estimate of the standard deviation with only two 
data points. The MRL for each analyte was determined by then rounding 
this number to two significant digits.
    Note that Method 525.2 was published before the LCMRL protocol was 
developed. Therefore, no LCMRL data are available for the analytes 
being determined using this method. The MRLs for acetochlor, alachlor, 
and metolachlor were determined using the same procedure used in UCMR 
1, i.e., multiplication of the highest individual laboratory method 
detection limit in the method by a factor of 10. Note also that there 
is a single MRL for perchlorate, although there are four methods 
approved for UCMR analyses. The value of 0.57 [mu]g/L is a mid-range 
value (and the MRL determined for Method 332.0) that is easily 
achievable for Methods 314.1, 331.0, and 332.0; and slightly more 
difficult to achieve using Method 314.0.
    LCMRLs were calculated by selected laboratories during analytical 
method development. There is no requirement for laboratories that are 
analyzing samples under the UCMR to determine LCMRLs. The procedure for 
LCMRL determination includes the following:
     Calibration curve analysis;
     Replicate sample analysis requirements;
     Linear regression procedures; and
     Outlier evaluation.
    The validation of laboratory performance at or below the MRL would 
be required to be performed by all laboratories that analyze samples 
under UCMR 2. Validation would consist of two procedures:
     As part of the Initial Demonstration of Capability (IDC) 
for each analytical method, each laboratory would need to process seven 
replicate samples, spiked at or below the MRL, through the entire 
method procedure (i.e., including extraction and with all 
preservatives, where applicable). This step would need to be performed 
for each analyte. Laboratories would be required to demonstrate that, 
based on the results of the seven replicates, their predicted range of 
results will fall, with 99 percent confidence, within 50 percent to 150 
percent recovery, inclusive.
     During sample analysis, laboratories would need to run a 
daily check sample to demonstrate that, at or below the MRL for each 
analyte, the measured recovery is within 50 percent to 150 percent, 
inclusive. The results for any analyte for which 50 percent to 150 
percent recovery cannot be demonstrated during the daily check would 
not be valid. Laboratories may elect to re-run the daily performance 
check sample if the performance for any analyte or analytes cannot be 
validated. If the performance for these analytes is validated, then the 
laboratory performance would be considered validated. If not, or as an 
alternative to analysis of a second check sample, the laboratory may 
re-calibrate and repeat the performance validation process for all 
analytes.
    Further details regarding these procedures are available through 
EPA's UCMR Web site (http://www.epa.gov/safewater/ucmr/ucmr2/index.html) in a document titled ``UCMR 2 Laboratory Approval 
Requirements and Information Document'' (USEPA, 2004k).

E. How Will Laboratories Conduct UCMR Analyses?

    All laboratories conducting analyses under this regulation must be 
approved by EPA to perform those analyses. Laboratories seeking 
approval must provide EPA with data that demonstrates their successful 
completion of an IDC as outlined in each method, verification of 
successful performance at the MRLs as specified in today's action, and 
successful participation in an EPA Proficiency Testing (PT) program for 
the analytes of interest. On-site audits of selected candidate 
laboratories may be conducted. Details of the EPA laboratory approval 
program are contained in the technical manual titled: ``UCMR 2 
Laboratory Approval Requirements and Information Document'' (USEPA, 
2004k). This document will be available on the electronic docket at: 
http://www.epa.gov/edocket/; or through EPA's UCMR Web site: http://www.epa.gov/safewater/ucmr/ucmr2/index.html. In addition, EPA may 
supply analytical reference standards for selected analytes to 
participating/approved laboratories.
1. Laboratory Approval Process for UCMR 2
    The UCMR 2 laboratory approval program is designed to assess and 
confirm the capability of laboratories to perform analyses using the 
methods listed in Table 1 of today's proposed rule, in Sec.  
141.40(a)(3). With the exception of EPA Method 525.2, the UCMR 2 
methods do not currently have an established certification program. 
Applicant laboratories that are already approved by their State or 
primacy entity to conduct drinking water analyses using Method 525.2 
will still need to perform the UCMR approval steps, including the 
related PT evaluation. The UCMR 2 laboratory approval process is 
designed to assess whether laboratories meet the required equipment, 
laboratory performance, and

[[Page 49109]]

data reporting criteria described in today's action. This evaluation 
program is voluntary in that it only applies to laboratories intending 
to analyze UCMR 2 drinking water samples. However, EPA will require 
systems to use UCMR 2-approved laboratories when conducting monitoring 
for those analytes listed in Table 1 of Sec.  141.40(a)(3) of this 
rule. A list of laboratories approved for UCMR 2 will be posted to 
EPA's UCMR Web site: http://www.epa.gov/safewater/ucmr/ucmr2/labs.html. 
Laboratories are encouraged to apply for UCMR 2 approvals as early as 
possible, as schedules for large PWS sampling will be completed soon 
after the final rule is promulgated. The steps for the laboratory 
approval process are as follows:
    a. Request to Participate. The laboratory must contact EPA 
requesting to participate in the UCMR 2 laboratory approval process. 
Laboratories must send this request to: UCMR 2 Laboratory Approval 
Coordinator, USEPA, Technical Support Center, 26 West Martin Luther 
King Drive (MS 140), Cincinnati, OH 45268; or e-mail at: [email protected]. EPA will begin accepting requests for 
registration forms for the methods associated with the UCMR Contaminant 
List (including List 1, Assessment Monitoring, and List 2, Screening 
Survey) beginning August 22, 2005. The laboratory must request the 
necessary registration forms within 90 days after final rule 
publication.
    b. Registration. EPA will send each laboratory that requests 
registration forms to conduct UCMR 2 analysis a list of information 
that EPA will need to process that application. This registration 
information will provide EPA with the basic information about the 
candidate laboratory: Laboratory name; mailing address; shipping 
address; contact name; phone number; fax number; e-mail address; and 
UCMR 2 methods for which the laboratory is seeking approval. Thus, the 
purpose of the registration step is to ensure that EPA has all of the 
necessary contact information, and that each laboratory receives a 
customized application package that will include materials and 
instructions for the methods that it plans to use.
    c. Application Package. When EPA receives the registration 
information, an application package will be sent to the laboratory for 
completion. This application package will be customized to address only 
those EPA methods selected in the laboratory's registration 
information. EPA may provide analytical standards to be used when 
conducting monitoring; however, laboratories will be required to 
procure their own standards, where commercially available, to be used 
to complete the application process. Information requested in the 
application will include:
     IDC data, including precision, accuracy, and MRL studies;
     Information regarding analytical equipment;
     Proof of current drinking water laboratory certification; 
and
     Example chromatograms for each method under review.
    The laboratory must also confirm that it will post UCMR 2 
monitoring results (on behalf of its PWS clients) to EPA's UCMR 
electronic data reporting system.
    d. EPA Review of Application Package. EPA will review the 
application package and, if necessary, request follow-up information. 
Satisfactory completion of this portion of the process will allow the 
laboratory to participate in the UCMR 2 PT program.
    e. Proficiency Testing. A PT sample is a synthetic sample 
containing a concentration of an analyte that is known to EPA, but 
unknown to the laboratory being tested. To complete the initial 
laboratory approval process, a laboratory must successfully analyze 
UCMR 2 PT sample(s) for each method for which the laboratory is seeking 
approval. EPA intends to offer up to four opportunities for a 
laboratory to successfully analyze the UCMR 2 PT samples. Up to three 
of these studies will be conducted prior to the publication of the 
final rule, but at least one study will be conducted after publication 
of the final rule. When a laboratory passes a PT for one of the UCMR 2 
methods, EPA will not send a PT sample for that method in later PT 
opportunities. Laboratories applying for UCMR 2 approval, and 
laboratories conducting UCMR 2 analyses, may be subject to on-site 
laboratory audits. No PT studies will be conducted after the start of 
monitoring. No laboratories will be approved that did not successfully 
complete a PT study.
    f. Written EPA Approval. After the first five steps (a. through e.) 
have been successfully completed, EPA will send the laboratory a letter 
listing the methods for which approval is pending (if the PT study and 
laboratory evaluation is conducted prior to promulgation of the final 
rule) or approval is granted (after promulgation of the final rule). 
Laboratories receiving a pending approval may be automatically approved 
following promulgation of the final rule, or they may need to repeat 
all or part of the approval process, contingent upon what changes are 
applied to the rule between proposal of the draft rule and promulgation 
of the final rule. These letters will also include a reminder that the 
laboratory may be subject to on-site audits.
2. Quality Control Requirements
    For UCMR 2, EPA has made several changes to the quality control 
requirements, which were previously located in Sec.  141.40, Appendix 
A. The quality control steps in Appendix A information will be moved to 
Sec.  141.40(a)(5). Requirements related to MRLs and to laboratory 
approvals will be incorporated into this section of the proposed rule, 
and are discussed in sections III.D and III.E.1, respectively. Changes 
related to the quality control requirements include:
     The language regarding Detection Limits will be replaced 
with the requirement to validate each laboratory's performance at or 
below the MRL. Since UCMR 1 was promulgated, EPA has developed new MRL 
and LCMRL procedures. The MRL procedures are now described in Sec.  
141.40(a)(5). Guidelines and procedures for using LCMRLs in 
establishing MRLs for UCMR 2 are described in this preamble, and in a 
document entitled: ``Statistical Protocol for the Determination of the 
Single-Laboratory Lowest Concentration Minimum Reporting Level (LCMRL) 
and Validation of the Minimum Reporting Level (MRL)'' (USEPA, 2004j).
     The calibration step will be changed to remove the 
requirement for acceptance ranges for each analytical method. Because 
all of the methods approved for UCMR 2 monitoring specify calibration 
acceptance criteria, it is not necessary to specify criteria in this 
rule.
     The requirement to analyze a field reagent blank (Reagent 
Blank Analysis) will be removed because the analysis of a field reagent 
blank is not required in any of the methods proposed for UCMR 2. None 
of the analytes being proposed are sufficiently hydrophobic or volatile 
enough for there to be a serious concern about sample contamination 
during shipping.
     The requirement to analyze Quality Control Samples will be 
removed since they are not available for the majority of the analytes 
contained in this rule.
     The terms Matrix Spike and Matrix Spike Duplicate will be 
replaced with Laboratory Fortified Sample Matrix and Laboratory 
Fortified Sample Matrix Duplicate, respectively, to be consistent with 
the terms specified in the data

[[Page 49110]]

elements table in Sec.  141.35(e) of today's proposed action.
     The language to describe Internal Standard Calibration 
will be modified to more clearly describe the requirements.
     The requirements regarding the Method Performance Test 
will not be changed.
     The requirements related to Detection Confirmation will be 
revised to be consistent with the methods being approved in this rule. 
Analytical results for perchlorate determined to be at or above the MRL 
using Methods 314.0 and 314.1 are required to be confirmed by a second 
chromatographic column, or by confirmation using Method 331.0 or 332.0, 
before being reported. Alternatively, the primary analysis of 
perchlorate may be conducted using either Method 331.0 or 332.0.
     Reporting requirements will be clarified and modified such 
that laboratories will be required to report their data to EPA's 
electronic data reporting system (http://www.epa.gov/safewater/ucmr/ucmr2/reporting.html) within 120 days of sample collection. PWSs have 
60 days from the laboratory posting to review, approve, and submit the 
data to the State and EPA via the electronic reporting system. After 60 
days from the laboratory's posting, if the PWS has not approved and 
submitted the data, the data will be considered approved and final for 
EPA review.
    No changes will be made to the requirements related to Sample 
Collection and Preservation other than the addition of the requirement 
for laboratories using Method 314.0 for the analysis of perchlorate to 
preserve their samples as required in the other approved perchlorate 
analysis methods. In addition, the requirements concerning Method 
Defined Quality Control will not be changed.

F. How Are Systems Selected for UCMR Monitoring?

1. How Are Systems Selected for Assessment Monitoring?
    a. Original Assessment Monitoring Statistical Approach for UCMR 1. 
Under UCMR 1, Assessment Monitoring was specified to be conducted by 
all large CWSs and NTNCWSs serving more than 10,000 people (e.g., a 
census of large systems, totaling approximately 3,100), and by a 
statistically representative sample of 800 small systems (systems 
serving 10,000 or fewer people). The large size of the stratified 
random sample allowed for a high level of confidence in the resulting 
monitoring data and low error or uncertainty within the sample. The 
List 1 contaminants monitored under Assessment Monitoring are the 
priority contaminants for which analytical methods have already been 
developed.
    EPA identified DQOs for the representative sample of small systems 
to include the following: data must provide unbiased national exposure 
estimates; and margins of error must be kept to 1 percent 
with 99 percent confidence for CWSs and 2.5 percent with 95 
percent confidence for NTNCWSs. Use of a standard statistical design 
formula to estimate the minimum sample size and an assumed estimated 
occurrence of approximately 1 percent resulted in a minimum sample size 
of 659 systems. The sample size was then adjusted upwards to account 
for additional DQOs. Furthermore, the sample was stratified across 
system size, water source, and type to account for differences in 
vulnerability, differential occurrence, and management capacity, as 
outlined below.
    The small system representative sample was designed to account for 
different system sizes, types of systems, sources of water supply, 
contaminants likely to be found, and geographic location (e.g., 
States), as outlined in SDWA section 1445(a)(2)(A). The sample was 
stratified considering the proportion of the population served by CWSs 
and NTNCWSs by water source type (i.e., ground or surface water) and 
system size category (i.e., serves 25 to 500 people, 501 to 3,300 
people, and 3,301 to 10,000 people) within the water source type. This 
stratification allowed EPA to account for different exposure risks of 
contaminant occurrence that may be related to the differential 
vulnerability of water sources and differing management and financial 
capacity that can vary across system types and sizes.
    EPA also allocated the selection of small systems across all the 
States and territories to account for differences in spatial 
vulnerability and contaminant occurrence and made adjustments to ensure 
equity in participation. Because contaminant exposure assessment was a 
primary goal of UCMR 1, EPA began with a base design that allocated 
systems to States in proportion to the population served. This 
population-weighted allocation leads to the best estimates of national 
exposure. However, this approach, when strictly applied, assigns small 
numbers of systems, or even zero systems, to the smallest States and 
territories. To ensure the sample was fully representative of the 
nation and to provide equity across States for involvement in the UCMR, 
EPA adjusted the population-based design to include at least two 
systems from each State and territory in the United States (with the 
exception of Guam, which had only one PWS that qualified). Small Tribal 
water systems in each of the 10 EPA Regions were grouped into a single 
category for the representative sample. Thus, the Tribal category was 
equivalent to a ``State'' for the statistical selection process, which 
ensured that Tribal systems would be selected. Exhibit 7 summarizes the 
system allocation across system sizes and water sources, including the 
adjustment for a minimum of two systems per State.

   Exhibit 7.--Approximate Sample Allocation for Assessment Monitoring: Expected Number of Systems Selected by
                                        System Size and Water Source \1\
----------------------------------------------------------------------------------------------------------------
                                                                                   Surface water
                          Size category                            Ground water     (and GWUDI)        Total
                                                                      systems       systems \2\
----------------------------------------------------------------------------------------------------------------
500 and Under...................................................             103              57             160
501 to 3,300....................................................             250              50             300
3,301 to 10,000.................................................             230             110             340
                                                                 -----------------
        Total...................................................             583             217            800
----------------------------------------------------------------------------------------------------------------
\1\ For more information see ``Statistical Design and Sample Selection for UCMR 1'' (USEPA, 2001c).
\2\ GWUDI = ground water under the influence of surface water.


[[Page 49111]]

    To provide an improved understanding of contaminants and conditions 
affecting small systems in UCMR 1, EPA selected 30 small PWSs from the 
systems in State Monitoring Plans as ``Index Systems'' at which 
contaminants would be monitored every year during the five-year cycle. 
EPA conducted the sampling and testing for the Index Systems. At the 
time of sampling, EPA also gathered other data to characterize the 
environmental setting affecting the system including precipitation, 
land and water resource use, and environmental data (such as soil type 
and geology).
    The details of the design are included in ``Statistical Design and 
Sample Selection for the UCMR 1'' (USEPA, 2001c). The design of UCMR 1 
was subjected to peer review and improved by recommendations of the 
peer reviewers, as well as from suggestions made during the public 
comment and response process in developing UCMR 1.
    b. Proposed Assessment Monitoring Statistical Approach for UCMR 2. 
EPA proposes to maintain the same basic statistical design for its UCMR 
2 national representative sample of 800 small systems and to continue 
with a census of large water systems for Assessment Monitoring. EPA 
believes that the combination of a nationally representative sample of 
small systems and a census of large systems provides a powerful tool 
for assessing contaminant occurrence in PWSs, and believes that this is 
the most effective and accurate survey approach, as long as methods, 
laboratory capacity, and cost issues allow for its implementation.
    EPA is proposing to eliminate Index System monitoring at small 
systems under UCMR 2 based on the lack of contaminant occurrence 
observed at Index Systems monitored in UCMR 1.
2. How Are Systems Selected for the Screening Survey?
    a. Original Screening Survey Statistical Approach for UCMR 1. The 
Screening Survey tier of UCMR 1 was designed as a statistical sample to 
assess contaminant occurrence in PWSs. However, because of the small 
number of systems, the resulting data were only designed to be used for 
national estimates. Individual strata had too large a variance to 
provide meaningful estimates. The Screening Survey, List 2 contaminants 
were those for which uncommon analytical methods were used. To ensure 
there was enough laboratory capacity to conduct these new, specialized 
analyses, the Screening Survey sample size was limited to 300 systems 
(120 large and 180 small PWSs). Screening Survey results from UCMR 1 
were generally expected to provide only enough information for EPA to 
determine whether a contaminant should be elevated to future Assessment 
Monitoring because at low occurrence there would be considerable 
uncertainty. Only at a relatively high level of occurrence could a 
contaminant be moved directly to regulatory determination using the 
UCMR 1 Screening Survey data.
    The Screening Survey sample of systems was randomly selected from 
the Assessment Monitoring sample pool to allow systems some efficiency 
in conducting sampling for both tiers of monitoring. Screening Surveys 
and Assessment Monitoring were scheduled to coincide for those small 
system systems selected for both. By design, large Screening Survey 
systems were selected from the pool of all large systems, as all were 
required to conduct Assessment Monitoring. However, there were 
difficulties with the sample selection for small systems because the 
sample pool was small. During either of the two UCMR 1 Screening Survey 
years, the sample pool was restricted to one-third of the Assessment 
Monitoring systems (approximately 267). Thus, the Screening Survey 
sample of 180 small systems represented approximately 67 percent of the 
available sample pool in a given year.
    In general, the smaller sample size of the Screening Surveys is 
associated with higher margins of error and lower confidence in 
estimating contaminant occurrence (compared to the larger Assessment 
Monitoring sample). Although the sample as a whole can provide 
nationally representative estimates, sample results cannot be 
subdivided to be representative of individual strata, as they can be 
with the larger Assessment Monitoring sample. In addition, uncertainty 
is high for low occurrence contaminants. The samples for each Screening 
Survey under UCMR 1 were allocated across five system size categories, 
as well as across ground water and surface water (and ground water 
under the direct influence of surface water (GWUDI)) systems, to 
provide coverage of differences in vulnerability that may exist. See 
Exhibit 8 for the sample allocation across system size and source water 
categories. Each size category was given equal importance with 60 
systems selected from each size category, and with the selected systems 
distributed evenly between surface water and ground water systems 
wherever possible (i.e., 30 ground water and 30 surface water systems 
were targeted to be selected to monitor for each Screening Survey). 
However, when there were not enough systems in a given size/source 
category, systems were allocated to the other source within that same 
size category. This was the case for small systems because of the 
restricted sample pool. This resulted in a uniform sample allocation 
across all size categories, with 180 small systems and 120 large 
systems in each of the two Screening Surveys. This distribution was 
used to provide a balance between population served and the number of 
systems. A sampling scheme weighted by population cannot include many 
small and very small systems; a scheme weighted by the number of 
systems served can include too many small systems at the expense of 
large systems (USEPA, 2001c).

             Exhibit 8.--UCMR 1 Design Allocation of Systems for Screening Surveys, by Size Category
----------------------------------------------------------------------------------------------------------------
                                                                                   Surface water
                          Size category                            Ground water     (and GWUDI)        Total
                                                                    systems \1\     systems \2\
----------------------------------------------------------------------------------------------------------------
                            Sample of Small Systems (serving 10,000 or fewer people)
----------------------------------------------------------------------------------------------------------------
500 and Under...................................................              30              30              60
501 to 3,300....................................................              30              30              60
3,301 to 10,000.................................................              30              30              60
    Subtotal Small Systems......................................              90              90             180
-----------------------------------------------------------------
                                 Large Systems (serving more than 10,000 people)
----------------------------------------------------------------------------------------------------------------
10,001 to 50,000................................................              30              30              60
50,001 and over.................................................              30              30              60

[[Page 49112]]

 
    Subtotal Large Systems......................................              60              60             120
                                                                 -----------------
        Total...................................................             150             150            300
----------------------------------------------------------------------------------------------------------------
\1\ Includes systems with all of their water supplied by a ground water source.
\2\ Includes systems with all or part of their source water supplied by surface water or GWUDI.

    b. Proposed Screening Survey Statistical Approach for UCMR 2. To 
increase the statistical strength of the Screening Survey sample, EPA 
proposes to include additional PWSs in the Screening Survey under UCMR 
2. The sample size will be increased in two ways to ensure the data can 
be used to support regulatory determinations and rule development, if 
warranted. Thus, if a contaminant of concern is found to occur with 
some significance during the Screening Survey, EPA may choose not to 
conduct Assessment Monitoring and move to make a regulatory 
determination based on these data to protect public health more 
quickly.
    The proposed new Screening Survey design also accounts for possible 
laboratory capacity issues related to the use of uncommon methods. The 
Screening Survey will be conducted across two years, rather than the 
one-year implementation period that was established under UCMR 1. 
Spreading the monitoring across two years will reduce the burden on the 
limited number of laboratories that will be capable of using these 
uncommon methods. In today's proposed rule, only one Screening Survey 
list is included, as compared to UCMR 1, in which separate Screening 
Survey lists were issued for chemical and microbial monitoring. As 
shown in the UCMR 2 time line in section III.K, Exhibit 10, EPA has 
left open the possibility of a second Screening Survey later in the 
UCMR 2 monitoring cycle, if necessary.
    The proposed design increases confidence in the sampling results in 
two ways. First, the Screening Survey would use a larger stratified 
random sample of approximately 800 systems (compared to 300 under UCMR 
1), allocated across five strata for systems serving 100,000 or fewer 
people. The sample size is derived from the same rationale as that for 
Assessment Monitoring, but the sample frame is expanded to include 
large systems serving between 10,001 and 100,000 people. Second, the 
Screening Survey will include a census of the largest PWSs, those 
serving more than 100,000 people (322 systems), referred to within this 
section as ``very large'' systems. Using a census of these very large 
systems will minimize the possibility of missing contaminant occurrence 
at the systems that serve the largest portion of the population, while 
keeping the number of systems required to conduct the Screening Survey 
relatively small. No small systems (those serving 10,000 or fewer 
people) will be selected to participate in more than one component of 
UCMR 2 (i.e., will monitor for only Assessment Monitoring or the 
Screening Survey).
    The sample of 800 systems serving 100,000 or fewer people will be 
divided uniformly among 10 strata (as used in past Screening Surveys 
under UCMR 1; see Exhibit 8). With the census of the systems serving 
100,001 people or more (approximately 322), plus the sample of 800 
systems, 1,122 water systems will monitor for the Screening Survey 
under UCMR 2.

                   Exhibit 9.--Allocation of Systems for Screening Survey, List 2 Contaminants
----------------------------------------------------------------------------------------------------------------
                                                                                                   Total systems
                          Size category                            Ground water    Surface water    (including
                                                                    systems \1\                     GWUDI) \2\
----------------------------------------------------------------------------------------------------------------
                            Sample of Small Systems (serving 10,000 or fewer people)
----------------------------------------------------------------------------------------------------------------
50 and under....................................................              80              80             160
501 to 3,300....................................................              80              80             160
3,301 to 10,000.................................................              80              80             160
                                                                 -----------------
    Subtotal Small Systems Sample...............................             240             240             480
-----------------------------------------------------------------
                           Sample of Large Systems (serving 10,001 to 100,000 people)
----------------------------------------------------------------------------------------------------------------
10,001 to 50,000................................................              80              80             160
50,001 to 100,000...............................................              80              80             160
                                                                 -----------------
    Subtotal Large Systems Sample...............................             160             160             320
 
-----------------------------------------------------------------
                       Census of Very Large Systems (serving greater than 100,000 people)
----------------------------------------------------------------------------------------------------------------
100,001 and over................................................              61             261             322
                                                                 -----------------
        Grand Total.............................................             461             661          1,122
----------------------------------------------------------------------------------------------------------------
\1\Includes systems with all of their water supplied by a ground water source.
\2\Includes systems with all or part of their source water supplied by surface water or GWUDI.


[[Page 49113]]

3. What Is UCMR Pre-Screen Testing?
    The third tier of UCMR 1, Pre-Screen Testing, was envisioned for 
use with methods that were in the early stages of development, and/or 
methods that were very specialized or limited in applicability. It was 
to be conducted by up to 200 PWSs that would be identified by State 
agencies as vulnerable to the List 3 contaminants. This testing would 
be a targeted sampling to assess occurrence in the most vulnerable 
settings, and could help to guide the next steps for contaminant 
evaluation as well as methods development. Although no Pre-Screen 
Testing has been scheduled to date, nor has any been proposed in this 
action, the Pre-Screen Testing design could still be a useful way to 
monitor for emerging contaminants with highly technical, specialized 
methods. Therefore, the rule retains the language related to Pre-Screen 
Testing that was part of the original rule.
4. What Are the Other Applicability Considerations?
    Applicability criteria for UCMR 2 remain similar to those under 
UCMR 1. The survey design for the Screening Survey is slightly 
different than that under UCMR 1, as described in section III.F.2. 
Specific UCMR 2 applicability criteria are described in Sec. Sec.  
141.40(a)(1) and (2) of today's proposed action. Notable changes or 
clarifications to the applicability criteria include the establishment 
of a clear date for rule applicability; a requirement to notify EPA in 
the case of changes to applicability; and clarification regarding the 
definition of system population, as follows:
    a. New Applicability Date. The applicability requirements for PWSs 
under UCMR 1 provided distinct criteria (e.g., system size, water 
source, etc.) which helped determine whether a system could be subject 
to UCMR monitoring requirements. However, a specific date was not 
prescribed in the UCMR 1 regulation to establish a cutoff date by which 
systems did or did not fit these criteria. This created uncertainty 
defining applicability over the course of the three-year monitoring 
period (2001-2003). EPA is proposing in Sec.  141.40(a) to establish 
the UCMR 2 applicability criterion that includes a specific 
applicability date of June 30, 2005, at which point a defined list of 
PWSs will be established as subject to the rule requirements.
    b. Notice Regarding Changes to Applicability Required. The proposed 
rule also includes an allowance for adjustments to a system's 
applicability status through reporting requirements in Sec.  
141.35(b)(2). During the course of UCMR 2 implementation, if a change 
occurs at a system that affects UCMR applicability or specific 
monitoring requirements (such as a change of source water, or closure 
of a sampling location), the system can send a letter to EPA explaining 
the changes and requesting appropriate changes to its monitoring 
requirements. However, to ensure that a system does not mistakenly 
discontinue monitoring, today's proposed action specifies that the 
system must continue to monitor according to established requirements 
until it receives written approval from EPA to change its requirements. 
EPA will address these requests on a case-by-case basis.
    c. Definition of System Population. Under UCMR 1, large PWSs were 
defined as those systems that served a population of more than 10,000 
individuals and small PWSs were those that served 10,000 or fewer 
people. While this included the sum of the population served by the 
combined distribution system this requirement was occasionally 
misunderstood. In today's proposed action EPA has explained more 
clearly that ``population served'' is the sum of the retail population 
served directly by the PWS plus the population served by any 
consecutive system(s) receiving all or part of its finished water from 
that PWS. As was established in the proposed Stage 2 Disinfectants and 
Disinfection Byproducts Rule (68 FR 49547, August 18, 2003 (USEPA, 
2003b)) EPA defines a ``consecutive system'' as a public water system 
that buys or otherwise receives some or all of its finished water from 
one or more wholesale systems.

G. When Must Monitoring Be Conducted?

1. Timing of Monitoring
    The timing of monitoring is a critical aspect of UCMR 
implementation. Similar to UCMR 1, the UCMR 2 program will have two 
components: Assessment Monitoring for List 1 contaminants, to be 
conducted July 2007-June 2010; and the Screening Survey for List 2 
contaminants, to be conducted July 2007-June 2009.
    For each component of UCMR 2, participating systems will collect 
samples as follows:
     Surface water sampling locations (including all sampling 
locations for which some or all of the water comes from a surface water 
or GWUDI source) will be sampled four times, three months apart, during 
a continuous 12-month period. These locations must be sampled in either 
the first, second, or third month of four consecutive quarters. 
Therefore, a system could conduct monitoring in either: (1) January, 
April, July, October; (2) February, May, August, November; or (3) 
March, June, September, December.
     Ground water sampling locations (including only those 
sampling locations at which all of the water comes from a ground water 
source) will be sampled two times, for six months apart, during a 
continuous 12-month period.
    The specific days of the week for sample collection and shipping 
are limited to ensure sample quality. Under both UCMR 1 and today's 
proposed UCMR 2, systems cannot collect samples on Friday, Saturday, or 
Sunday. The reason stated within the UCMR 1 language was that samples 
needed to be shipped and received at the laboratory within 30 hours of 
sampling to accommodate requirements for the sampling of 
microbiological parameters, as well as to assure that the samples were 
received within the required temperature range. A 30-hour turn-around 
time is sometimes not possible to achieve and there are no 
microbiological parameters included in this action. Therefore today's 
action proposes to replace the 30-hour turn-around time with the 
requirement that samples be shipped and received at the laboratory at 
the required temperature to maintain sample quality.
2. Individual PWS Monitoring Schedules
    Based on lessons learned during UCMR 1 implementation, EPA intends 
to establish schedules for large system monitoring to ensure adequate 
laboratory capacity for the analysis of UCMR contaminants, and to 
improve the oversight of monitoring and data reporting. Under UCMR 1, 
EPA specified the year and months in which small systems would monitor, 
for both Assessment Monitoring and the Screening Surveys, to ensure 
coverage related to spatial and temporal monitoring, and to enable 
scheduling of laboratory analyses and shipping of sampling materials 
(all of which EPA paid for). However, schedules for large systems only 
specified a particular year for Screening Surveys. For Assessment 
Monitoring, large systems could select their year and months of 
monitoring, within a three-year window. Large systems were not required 
to notify EPA of their Assessment Monitoring schedule, and many opted 
to conduct monitoring during the last possible year, which created some 
implementation problems. EPA was not able to project

[[Page 49114]]

the numbers of PWSs or identify the individual PWSs that had failed to 
comply with the UCMR 1 requirements until well into the final 
monitoring year, making compliance assistance more difficult. Greater 
scheduling flexibility was believed justified for UCMR 1 because the 
majority of the approved UCMR 1 analytical methods were also approved 
for established compliance monitoring. This flexibility allowed for 
possible cost savings on laboratory fees and sample collection burden. 
In contrast, UCMR 2 methods are not appropriate for compliance 
monitoring (with the exception of Method 525.2, which has been added to 
allow for the monitoring of both the acetanilide degradates, and the 
parent compounds).
    EPA will use the State Monitoring Plans \4\ to identify all small 
and large systems that will participate in the UCMR program, and to 
identify the monitoring schedule for each system. More specifically, 
EPA will send each State an initial State Monitoring Plan that lists 
all small and large systems that are subject to the UCMR requirements, 
and an initial schedule for sampling (year and months) for each system. 
In the initial State Monitoring Plans for each State, approximately 
one-third of the PWSs will be scheduled to conduct Assessment 
Monitoring in each continuous 12-month period during July 2007 through 
June 2010 and approximately one-half of the PWSs will be scheduled to 
conduct the Screening Survey in each continuous 12-month period during 
July 2007 through June 2009. States that enter into Partnership 
Agreements (PAs) with EPA will have the option to review and revise PWS 
monitoring schedules as part of their modifications to the State 
Monitoring Plans.
---------------------------------------------------------------------------

    \4\ Under UCMR 1, initial State Monitoring Plans included 
tabular listings of the small systems selected to conduct Assessment 
Monitoring and listings of all systems (small and large) selected to 
conduct Screening Survey monitoring. Initial State Monitoring Plans 
also included instructions to States for revising and/or correcting 
their State Monitoring Plans, including modifications to sampling 
schedules for small systems. EPA incorporated revisions from States 
and returned the final State Monitoring Plans to each State.
---------------------------------------------------------------------------

    EPA will incorporate State revisions to the final State Monitoring 
Plans, including the sampling schedule revisions, if system 
participation is allocated approximately evenly across the years of 
monitoring. PWSs will be notified of their schedules by either EPA or 
the State, as determined through PAs (see section III.I of today's 
action for discussion of PAs). Large PWSs that meet the UCMR 2 
applicability criteria will be required to conduct UCMR 2 Assessment 
Monitoring, regardless of whether they are notified of a sampling 
schedule by EPA or the State.
    Large systems will have 210 days from the publication of the final 
rule to revise their schedule using the EPA electronic data reporting 
system. Following this 210-day period, if a large PWS cannot sample 
according to the required schedule (e.g., if a sampling location is 
closed for more than 15 days before and after the scheduled 
monitoring), the PWS must send a letter to EPA explaining the reason 
samples cannot be taken according to the assigned schedule, and 
requesting an alternative schedule, either: (1) To UCMR Sampling 
Coordinator, USEPA, Technical Support Center, 26 West Martin Luther 
King Drive (MS 140), Cincinnati, OH 45268; or (2) by e-mail at [email protected].

H. Where Are Samples Collected?

    For UCMR 2 monitoring, EPA proposes that all Assessment Monitoring 
sampling locations be entry points to the distribution system (EPTDSs). 
Under UCMR 1, ``raw source water'' sampling was allowed (if required by 
the State for compliance monitoring of regulated contaminants). 
However, if a system monitoring its source water detected any 
contaminants above the MRL concentration during UCMR 1 (and treatment 
was subsequently applied), the system was required to initiate 
monitoring at EPTDSs. EPA proposes to eliminate the option of source 
water monitoring under UCMR 2 (except for source water that leaves the 
EPTDS untreated) because:
     This created confusion and errant reporting for systems 
during UCMR 1; and
     The methods being proposed for UCMR 2 are generally not 
applicable to regulated contaminant monitoring, with the exception of 
Method 525.2; thus, UCMR 2 samples cannot be used to meet regulatory 
requirements, and no savings can be realized through use of multi-
analyte methods that coincide with those for regulated contaminants.
    EPA is proposing that the List 2 Screening Survey sampling 
locations be a combination of EPTDSs and distribution system sampling 
points. Monitoring for all the List 2 contaminants would be conducted 
at EPTDS sampling points. In addition to the EPTDS sampling location, 
monitoring for the nitrosamines would also be conducted at a sampling 
point location in the distribution system in order to capture the 
occurrence of NDMA as a disinfection byproduct (DBP). Both free 
chlorine and chloramines have been shown to form NDMA, but the rate of 
formation is slow, making it likely that NDMA concentrations will 
increase in the distribution system (Mitch and Sedlak, 2002). Thus, EPA 
is proposing that systems use their Stage 1 Disinfection Byproduct Rule 
(DBPR) maximum residence time sampling locations for the collection of 
distribution system samples for nitrosamine analyses. Systems with 
multiple treatment plants or sources of disinfected water will have a 
distribution system maximum residence time (DSMRT) sampling point 
associated with each plant/water source as defined in the Stage 1 DBPR 
(Sec.  141.132(b)(1)(i)). However, for some of the water systems that 
are required to conduct Screening Survey monitoring, the DSMRT sampling 
location may not be previously defined. Water systems that do not apply 
a chemical disinfectant, and wholesalers who do not have retail 
customers may not have defined DSMRT sampling points in the 
distribution system. For those cases, EPA is proposing that the 
nitrosamine samples be collected only at EPTDSs. EPA is requesting 
comment on whether or not nitrosamine samples should be collected at 
both the DSMRT sampling location and the EPTDS location or only at the 
DSMRT sampling location.
    EPA is also proposing language to allow large systems that use 
ground water sources and have multiple EPTDSs to conduct monitoring at 
representative entry point(s) rather than at each EPTDS. Many systems 
with multiple ground water EPTDSs suggested to EPA during UCMR 1 that 
these wells are often representative of the same source of ground water 
(e.g., because they come from the same aquifer in the same well field). 
To monitor at representative EPTDSs, systems must meet the criteria 
specified in Sec.  141.35(c)(3), and receive approval from EPA or the 
State (refer to section III.J.1 for a discussion of the criteria and 
necessary documentation).

I. What Is the States' Role in the UCMR Program?

    Under UCMR 2, EPA is clarifying States' potential role in rule 
implementation. EPA will narrow the optional activities under 
Partnership Agreements (PAs), formerly referred to as ``Memoranda of 
Agreement,'' so that implementation responsibilities will be clearer. 
Under UCMR 1, EPA included regulatory language that described some 
implementation and oversight activities that States could agree to 
through the PA process. However, because the UCMR is a direct 
implementation rule, State participation is voluntary. Specific 
activities for individual States are

[[Page 49115]]

identified and established through the PAs, not through rule language. 
Thus to streamline the language for UCMR 2, EPA has deleted this non-
rule language. EPA has retained the language related to the Governors' 
petition process (see Sec.  141.40(b)(1)), and the State-wide waiver 
provision (see Sec.  141.40(b)(2)).
    One new responsibility under the PAs that States may choose to 
accept will be the review and approval of proposals for representative 
EPTDSs that are submitted by ground water systems. In addition, EPA 
will expand the State Monitoring Plans to include all PWSs that are 
subject to UCMR (as compared to UCMR 1 State Monitoring Plans, which 
included just those selected for the statistical samples). These 
changes are described further below.
1. State Participation in Partnership Agreements (PAs)
    The statute provides a role for States in developing a 
representative monitoring plan for small systems (SDWA section 
1445(a)(2)(C)(i)). In addition, States/Primacy agencies most often have 
the best information about PWSs in their State. Through PAs, States can 
help EPA implement the UCMR program and help ensure that the UCMR data 
used for future regulatory determinations will be of the highest 
quality possible. During UCMR 1 implementation, State assistance with 
implementation was critical to the success of the program and was 
greatly appreciated by the Agency. EPA would like to continue to build 
upon these partnerships by soliciting participation from the States 
through the PA vehicle for UCMR 2. However, under UCMR 2, EPA plans to 
simplify the PAs. The UCMR 1 PA was complex, with 43 assistance tasks 
that States could perform or defer to EPA to act on.
2. Activities To Be Included in the UCMR 2 PAs
    The PA activity list under UCMR 2 is substantially shorter than 
that under UCMR 1 and will include a list of key activities for 
partnering States to perform, as discussed in this section. All States 
that agree to partner with EPA will be asked to review and provide any 
needed revisions to the State Monitoring Plan. Each State may agree to 
accept additional responsibilities as documented through each State's 
final PA with EPA. The primary potential State activities are discussed 
in sections a through c below. In addition, States that have assumed 
full partnership responsibilities may assist systems with their 
monitoring and reporting requirements, though the systems are 
ultimately responsible for compliance with their UCMR requirements.
    a. Review and Revision of the Initial State Monitoring Plan. EPA 
will send each State an initial State Monitoring Plan that will 
identify the statistically selected systems for Assessment Monitoring 
and Screening Survey monitoring, and all other large systems that are 
subject to UCMR 2 requirements and applicability criteria (see 
discussion of UCMR 2 system selection in section III.F of today's 
action). For the statistically selected systems, EPA will provide a 
list of similar replacement systems from which States can select to 
replace systems that may not have been appropriately specified in the 
initial plan. If the State agrees to partner with EPA, the State will 
be asked to notify EPA that it either accepts the State Monitoring Plan 
as is, or provide a written request with proposed modifications to the 
plan. Specific timing of the State Monitoring Plan coordination will be 
addressed in the PAs. State modifications can include any or all of the 
following allowed changes:

     Replace or update information on systems. A State can 
modify its State Monitoring Plan by removing systems that have 
closed, merged, or are purchasing all of their water from another 
system. If a State believes there are other reasons for removal from 
the initial plan, it will be asked to identify those systems, and 
provide an explanation for removal, in the request to modify the 
initial plan. If a State believes there are large systems (those 
serving more than 10,000 people) within their State that have not 
been included on the list of Assessment Monitoring systems, the 
State will be asked to identify those systems, and provide an 
explanation for their inclusion in the request to modify the initial 
plan. Information about the actual or potential occurrence or non-
occurrence of contaminants at a system, or a system's vulnerability 
to contamination cannot be used as a basis for removal from or 
addition to the plan. For the set of statistically selected systems, 
a State will be asked to replace any system it removes with systems 
from the replacement list, selecting replacements in the order they 
are listed.
     Modify the timing of monitoring for systems. A State 
may also modify the plan by recommending changes to the timing of 
monitoring for any system by selecting an alternative schedule (year 
and months) within the years specified for Assessment Monitoring or 
the Screening Survey. One reason a State may chose to modify the 
timing for system sampling could be to coordinate monitoring with 
regulated contaminant compliance monitoring. As long as system 
participation is allocated approximately evenly across the years of 
monitoring, the schedule can be modified for any system in the 
initial plan.

    b. Review and Approval of PWS Proposed Representative EPTDS. As 
discussed in section III.H, some large systems that use ground water as 
a source and have multiple EPTDSs may propose monitoring at 
representative entry point(s) rather than at each EPTDS. Large PWSs 
that have State-approved alternate EPTDS sampling locations, as 
provided for under Sec. Sec.  141.23(a)(1), 141.24(f)(1), and 
141.24(h)(1), may submit a copy of documentation from their State that 
approves their alternative sampling plan for EPTDSs. PWSs that do not 
have an approved alternative EPTDS sampling plan may submit a proposal 
to sample at representative EPTDS(s) rather than at each individual 
EPTDS if: They use ground water as a source; all of their well sources 
have either the same treatment or no treatment; and they have an EPTDS 
for each well within a well field (resulting in multiple EPTDSs from 
the same source, such as an aquifer). The existing approval 
documentation from the State or the representative well proposal, as 
appropriate, must be submitted to the UCMR Sampling Coordinator within 
120 days after publication of the final UCMR 2 regulation. EPA or the 
State will review the proposal, coordinate any necessary changes with 
the system, and approve the final list of EPTDSs where the system will 
be required to monitor. No plan will be final until the system receives 
written approval from EPA or the State.
    c. Notification and Instructions for Systems. If a State agrees to 
notify their systems, then within 30 days of receiving their final 
State Monitoring Plan, the State will be asked to notify all systems in 
that final plan of their monitoring and reporting requirements under 
UCMR, including sampling schedules. In addition, for each small system 
in the plan (i.e., those serving 10,000 or fewer people), the State 
will be asked to provide instructions on location, frequency, timing of 
sampling, use of sampling equipment, and handling and shipment of 
samples based on these regulations. EPA will provide States with 
guidance and templates for these small system instructions. States that 
perform the sampling or change the arrangements for the monitoring at 
the small systems in the plan will be asked to address these 
alternative monitoring arrangements in their PAs.
    As part of the agreement to conduct system notification, partnering 
States will be asked to provide an electronic listing of all PWSs that 
have been notified within 30 days of that notification. The list should 
be e-mailed

[[Page 49116]]

in flat file or standard spreadsheet format (such as Microsoft[reg] 
Excel) to: [email protected], and should include the 
PWS identification (PWSID) code and the date notification was sent to 
each system. A representative sample of the notice letter should also 
be included.
3. What If States Do Not Participate in a PA?
    Although EPA encourages each State to participate in a PA, States 
can choose not to enter into this agreement with EPA. In this event, 
the initial State Monitoring Plan that EPA sends the State will become 
the final State Monitoring Plan for that State and EPA will manage all 
UCMR-related activities, coordinating directly with affected PWSs in 
that State.

J. What Are the Data Reporting Requirements?

    Under the current unregulated contaminant monitoring program, 
reporting requirements exist at Sec.  141.35. Today's proposed action 
modifies those requirements to make reported results most useful for 
sound scientific analyses of the occurrence of unregulated 
contaminants. The proposed UCMR program identifies 15 data elements in 
Sec.  141.35(e), Table 1, that must be reported with unregulated 
contaminant sample test results. Large systems conducting Assessment 
Monitoring must include data elements 1 through 5, and 7 through 15 
with each sample result. Large systems conducting Screening Survey must 
include elements 1 through 15 with each result. Small systems must 
record key data elements on each sample form and bottle. Small systems 
conducting Assessment Monitoring must include elements 1 through 5, and 
7; and those conducting Screening Survey must include elements 1 
through 7. With today's proposed changes to Table 1 in Sec.  141.35(e), 
some of the reporting requirements will remain the same, a few are 
clarified, some have been removed, and three new additional data 
elements are being proposed. A minor change that has been applied to 
many of the data elements is a change in nomenclature from 
``identification numbers'' to ``identification codes'' to allow for the 
instances when alphanumeric identifiers are necessary.
    Other additions and clarifications to Sec.  141.35 are proposed for 
reporting that is required prior to and during monitoring. The purpose 
of these changes is to establish clear, enforceable locations and time 
frames for each system's UCMR monitoring, and to ensure that other 
critical rule-related information is communicated to EPA, such as 
changes to a system's applicability under the rule.
    Requirements in today's proposed action that are intended to ensure 
communication regarding rule applicability and compliance include 
reporting of changes in system status or other factors that affect a 
system's requirements under the rule (such as if a system believes it 
does not meet the applicability criteria for UCMR); reporting to EPA if 
a system believes it is subject to UCMR requirements, yet has not been 
notified by either EPA or the State regarding requirements; and 
reporting to EPA if a system cannot sample according to its assigned 
schedule (e.g., budget constraints, unavailability of sampling location 
during scheduled month of monitoring).
    Requirements and restrictions in today's proposed action related to 
reporting of monitoring data are as follows: Systems cannot report 
previously collected sampling data (because compliance with UCMR 2 
requires the use of uncommon analytical methods, most of which have 
been developed specifically for UCMR 2 contaminants); and systems 
reporting more than one set of results for the same sampling location 
and event will have the highest of the reported values as the official 
result.
    EPA is proposing through today's action that large systems report 
contact information, sampling location inventory information, and 
monitoring results to EPA's electronic data reporting system: http://www.epa.gov/safewater/ucmr/ucmr2/reporting.html. Today's proposed 
action also specifies that communications requiring written 
explanations or copies of documentation be sent either: (1) To UCMR 
Sampling Coordinator, USEPA, Technical Support Center, 26 West Martin 
Luther King Drive (MS 140), Cincinnati, OH 45268; or (2) by e-mail at 
[email protected]. This information may be entered by 
the PWS, their State, laboratory, or other representative of the PWS; 
however, the PWSs is ultimately responsible for compliance with this 
requirement.
1. What Information Is Required Prior To Monitoring?
    a. Contact Information. As with UCMR 1, large systems are required 
to report contact information to EPA. Today's proposed action clarifies 
that this information must be sent within 90 days of final rule 
publication, and specifies that the information must be submitted to 
EPA's electronic data reporting system. Today's proposed action also 
specifies that for small systems, EPA will send a letter requesting 
specific contact information. Those small systems, or the partnered 
State, must fill in the required information and return it within 90 
days of receiving the request.
    b. Sampling Location and Inventory Information. EPA is proposing 
that large PWSs provide inventory information for each applicable 
sampling location. This information must be reported through EPA's 
electronic reporting system within 210 days of final rule publication. 
For each sampling location, or for each approved representative 
sampling location (see the following section, III.J.1.c for information 
about representative sampling locations), large PWSs must submit the 
following information: PWSID code; PWS facility identification code; 
sampling point identification code; sampling point type identification 
code; and sampling location water type.
    In addition, large systems that are required to conduct Screening 
Survey monitoring must also report the disinfectant(s) used to maintain 
a residual in the distribution system for each distribution system 
sampling location (see section III.J.3.a for discussion of these 
reporting elements). All systems serving more than 10,000 people must 
ensure that the information concerning the disinfectants used, are 
submitted along with the sample results.
    c. Proposals for Ground Water Representative Sampling Locations. 
Some large systems that use ground water as a source and have multiple 
EPTDSs may propose monitoring at representative entry point(s) rather 
than at each EPTDS. Large PWSs that have State-approved alternate EPTDS 
sampling locations, as provided for under Sec. Sec.  141.23(a)(1), 
141.24(f)(1), and 141.24(h)(1), may submit a copy of documentation from 
their State that approves their alternative sampling plan for EPTDSs. 
PWSs that do not have an approved alternative EPTDS sampling plan may 
submit a proposal to sample at representative EPTDS(s) rather than at 
each individual EPTDS if: They use ground water as a source; all of 
their well sources have either the same treatment or no treatment; and 
they have an EPTDS for each well within a well field (resulting in 
multiple EPTDSs from the same source, such as an aquifer). The existing 
approval documentation from the State or the representative well 
proposal, as appropriate, must be submitted to the UCMR Sampling 
Coordinator within 120 days after publication of the final UCMR 2 
regulation. EPA or the State will review the proposal, coordinate any

[[Page 49117]]

necessary changes with the system, and approve the final list of EPTDSs 
where the system will be required to monitor. No plan will be final 
until the system receives written approval from EPA or the State.
    The proposal must demonstrate that any EPTDS selected as 
representative of the ground water supplied from multiple wells is 
associated with an individual well that draws from the same aquifer as 
the multiple wells (i.e., those being represented). For each 
representative sampling location in the proposal, systems must include 
the following information: PWSID, facility identification code, and 
sampling point identification code. In addition, the proposal must 
include supporting documentation, which can include system-maintained 
well logs or construction drawings indicating comparable depths 
(relative to elevation datum) of screened intervals and details of well 
casings and grouting; data demonstrating relative homogeneity of water 
quality constituents (e.g., pH, dissolved oxygen, conductivity, iron, 
manganese) in samples drawn from each well; and data showing that the 
wells are located in a limited geographic area (e.g., all wells within 
a 0.5 mile radius) and/or, if available, the hydrogeologic data 
indicating time of travel separating the representative well from each 
of the individual wells it represents (e.g., all wells within a five-
year time of travel delineation).
2. When Must Monitoring Results Be Reported?
    a. Large Systems. Today's proposed action establishes the timing of 
large system review and approval of monitoring data, as follows: 
Systems must ensure that their laboratory posts the data in EPA's 
electronic data reporting system (http://www.epa.gov/safewater/ucmr/ucmr2/reporting.html) within 120 days from the sample collection date; 
systems then have 60 days from when the laboratory posts the data in 
EPA's electronic data reporting system to review, approve, and submit 
the data to the State and EPA via the EPA electronic reporting system; 
if systems do not take action on the data within 60 days of the 
laboratory's posting to the electronic reporting system, the data will 
be considered approved by the system, and available for EPA review, 
prior to public release.
    b. Small Systems. Because EPA pays for and organizes the small 
system testing program, the review and approval step for small systems 
differs. Under today's proposed action, small systems would only be 
required to record system and sample location information on the 
sampling forms and bottles that are sent to them by the UCMR Sampling 
Coordinator. Procedures for submitting this information will be 
specified in the instructions sent to the system. Small systems will 
not be required to review monitoring results, although they will be 
given a 60-day opportunity to review such results prior to their 
results being posted to the publicly available Web site.
3. What Data Elements Are Required With the Monitoring Results?
    a. New Data Elements. EPA is proposing to add three new data 
elements: Water Source Type, Disinfectant Type, and Sample Event Code. 
Each is discussed in more detail as follows:
     Water Source Type: A system's water source type dictates 
the monitoring frequency (i.e., monitoring is conducted during four 
consecutive quarters for surface water/GWUDI sampling locations and 
twice during the monitoring year for ground water sampling locations). 
Reporting of this data element will help EPA ensure that systems are 
collecting samples at the required frequency. Systems are required to 
report either of the following codes for each sampling location:

--SW = surface water (to be reported if the sampling location is served 
all or in part by a surface water source);
--GW = ground water (to be reported if the sampling location is served 
entirely by a ground water source); and
--GU = GWUDI (to be reported for water facilities that are served all 
or in part by ground water under the direct influence of surface 
water).

     Disinfectant Residual Type: This data element will 
identify the type of disinfectant used to maintain a residual in the 
distribution system. The nitrosamine, NDMA (one of the Screening Survey 
contaminants), has been shown to form in chlorinated or chloraminated 
water as a DBP. Thus, EPA is interested in identifying the type of 
disinfectant used to maintain a disinfection residual in the 
distribution system, including whether a disinfectant residual is 
applied. Reporting of this data element only applies to those systems 
that are subject to Screening Survey monitoring. These systems will be 
required to verify that each of the disinfectant code(s) that indicate 
the type or types of treatment used to maintain a disinfectant residual 
in the distribution system be reported for each Screening Survey 
sampling location, as follows:

--CL = chlorine;
--CA = chloramine;
--OT = all other types of disinfectant (e.g., chlorine dioxide); and
--ND = no disinfectant used.

     Sample Event Code: This code will provide EPA with a 
unique identifier to associate reported field sample analytical results 
with a sampling event and, thus, allow the Agency to track whether 
scheduled monitoring has been completed. Using this code, PWSs will be 
required to keep EPA informed of any problems with their monitoring 
schedule for any given sampling event. For example, if resampling was 
needed due to problems with laboratory analyses, the system must inform 
EPA of which scheduled sampling event was being fulfilled by the 
results of the (unscheduled) resampling by using the Sample Event Code.
    b. Unchanged Data Elements. There will be no changes to the 
reporting requirements for the following data elements: Public Water 
System Identification (PWSID) code, Sample Collection Date, Analytical 
Method Code, and Analytical Results--Sign.
    c. Modified Data Elements. The following data reporting elements 
have been modified.
     Public Water System Facility Identification Code--Sampling 
Point Identification Code and Sampling Point Type Identification: 
During UCMR 1, Public Water System Facility Identification Code--
Sampling Point Identification Code, and Sampling Point Type 
Identification were all contained in the same data element. EPA is 
proposing to separate these into three individual data elements, and to 
clarify the meaning of each, with changes that include:

--for Public Water System Facility Identification Code, a shorter, 
clearer definition, with length of the code specified as five digits;
--for Sample Point Identification Code, a revised definition which 
specifies that the same identification code must be used consistently 
for all current and future unregulated contaminant monitoring to 
represent the UCMR sampling location; and
--for Sampling Point Type Identification Code, a limitation for UCMR 2 
to ``EP'' for entry point to the distribution system and ``MR'' for 
Stage 1 DBPR maximum residence time in distribution system because 
sampling under UCMR 2 will be limited to those two sampling locations. 
Eliminating codes for other sampling point types is intended to reduce 
confusion.

     Sample Identification Code: The size of the Sample 
Identification Code

[[Page 49118]]

has been expanded to include an alphanumeric value of up to 30 
characters (formerly capped at 15) assigned by the laboratory. The 
sample identification code will uniquely identify containers, or groups 
of containers, which hold the water samples collected at the same PWS/
facility/sampling location during the same sample collection date. This 
proposed action clarifies that the sample identification code must be 
unique to the sampling event within a PWS for each laboratory. A 
laboratory may not use the same sample identification code for more 
than one sampling event.
     Contaminant/Parameter: Because there are no water quality 
parameters being monitored in this proposed regulation, the 
Contaminant/Parameter data element is being revised to remove 
``Parameter'' from the data element name, and the definition is being 
revised to reflect this change.
     Analytical Result--Value: Because the requirement to 
report the MRL is being removed, the definition of Analytical Result--
Value is being revised to remove the requirement to report the MRL when 
the analytical result is less than the MRL.
     Sample Analysis Type: Sample Analysis Type is proposed to 
be revised to better reflect the type of sample collected. Previously, 
this data element could have four values: RFS (raw field sample), RDS 
(raw duplicate sample), TFS (treated field sample), or TDS (treated 
duplicate sample). These values were reported by the laboratory, which 
proved to be problematic, since the laboratory did not possess enough 
knowledge about the PWS treatment system or the location from which the 
sample was taken to be able to properly assign the correct sample 
analysis type. EPA is proposing to change the reporting requirements 
such that laboratories will be able to better define the sample 
analysis type with the following:

--FS = Field Sample, collected to fulfill the UCMR monitoring 
requirements;
--LFSM = Laboratory Fortified Sample Matrix, UCMR field sample with a 
known amount of the contaminant of interest added, associated with 
precision and accuracy;
--LFSMD = Laboratory Fortified Sample Matrix Duplicate, duplicate of 
the laboratory fortified sample matrix; and
--CF = Concentration Fortified, the concentration of a known 
contaminant added to a field sample.

This change will allow EPA to collect quality control information at 
the FS level instead of a laboratory batch level, and will allow EPA to 
know which UCMR FS was fortified. One UCMR FS should be fortified in 
duplicate within each analytical batch containing a UCMR sample. EPA 
will calculate precision and accuracy of the aggregate UCMR 2 
monitoring data using the individual quality control data reported by 
systems.

     Laboratory Identification Code: This data element was 
formerly part of the Sample Batch Identification Code. Since batch 
identification is being eliminated, Laboratory Identification Code is 
being kept as a stand-alone data element. The value will be an EPA-
assigned laboratory identification code.
    d. Data Elements No Longer Reported. EPA is proposing to no longer 
use the following eight data elements: Analytical Result--Unit of 
Measure; Minimum Reporting Level (MRL); MRL Unit of Measure; Sample 
Batch Identification Code; Analytical Precision; Analytical Accuracy; 
and Presence/Absence.
     Analytical Result--Unit of Measure, Minimum Reporting 
Level (MRL), and MRL Unit of Measure: Each of these data elements are 
predefined by today's proposed action. All laboratories analyzing UCMR 
samples will use the same MRL and unit of measure for UCMR analyses. 
EPA's electronic data reporting system will be populated with the 
correct values for MRL and unit of measure, so there is no need to 
report these data elements.
     Sample Batch Identification Code, Analytical Precision, 
and Analytical Accuracy: These data elements are related to laboratory 
quality control information and laboratory batches. To simplify 
reporting, EPA is removing requirements to report batches. With the 
removal of batches, the reporting of associated quality control data 
such as accuracy and precision will change. Accuracy and precision will 
be automatically calculated by the data system as follows:

--Precision: Analytical precision will be calculated from reported 
results for LFSM and LFSMD. Precision is the degree of agreement 
between two repeated measurements and is monitored through the use of 
duplicate fortified samples. For purposes of the UCMR, analytical 
precision is defined as the relative percent difference (RPD) between 
spiked duplicates analyzed in the same batch of samples as the 
analytical result. Precision is calculated as RPD between fortified 
matrix duplicates using:

RPD = [(X1 - X2) / {(X1 + 
X2)/ 2{time} ] x 100

Where:

    X1 is the measured concentration of the LFSM; and
    X2 is the measured concentration of the LFSMD.
--Accuracy: Analytical accuracy will be calculated from reported 
results for FS, LFSM, and CF. For purposes of the UCMR, analytical 
accuracy is defined as the percent recovery of the contaminant in the 
LFSM analyzed in the same analytical batch as the associated FS result 
and calculated using:
% recovery = [(concentration found in fortified sample - concentration 
found in sample)/ concentration fortified] x 100.

     Presence/Absence: This previously reserved data element 
was removed from the required list, as there are no analyses currently 
proposed on UCMR 2 that would require a presence/absence indicator.

K. Time Line of UCMR Activities

    Monitoring under UCMR 2 is scheduled for July 2007 through June 
2010. Preparation will begin prior to 2007 and will include 
coordination of laboratory approval, selection of representative 
samples of systems, development of State Monitoring Plans, and 
notification of participating PWSs. Assessment Monitoring for List 1 
contaminants will be conducted from July 2007 through June 2010. The 
Screening Survey for List 2 contaminants will be conducted from July 
2007 through June 2009. Exhibit 10 illustrates the major activities 
that will take place in preparation for and during implementation of 
UCMR 2.
BILLING CODE 6560-50-P

[[Page 49119]]

[GRAPHIC] [TIFF OMITTED] TP22AU05.003

BILLING CODE 6560-50-C

[[Page 49120]]

    To minimize the impact of the rule on small systems (those serving 
10,000 or fewer people), EPA will pay for the sample kit preparation, 
sample shipping fees, and analysis costs for these systems. In 
addition, no small system will be required to monitor for more than one 
monitoring list of UCMR 2. Large systems (those serving more than 
10,000 people) will pay for the cost of shipping and laboratory 
testing. Large systems will be responsible for reviewing, approving, 
and submitting (i.e., ``reporting'') monitoring results to EPA. Large 
systems have 60 days from when the laboratory posts the data to then 
review, approve, and submit the data to the State and EPA, via EPA's 
electronic data reporting system. If they do not electronically approve 
the laboratory data within 60 days of the laboratory's posting to EPA's 
electronic reporting system, the data will be considered approved and 
final for EPA review. EPA and the State will conduct its quality 
control review of the data for 60 days after the system reports the 
data. This will also allow for quality control review by States. After 
the quality control review, EPA will place the data in the national 
NCOD at the time of the next database update.
1. Assessment Monitoring
    Assessment Monitoring for List 1 contaminants will conducted from 
July 2007 through June 2010 by all large systems (those systems serving 
more than 10,000 people), and by a nationally representative sample of 
800 small systems (those serving 10,000 people or fewer). Samples will 
be collected from EPTDSs. However, as clarified in today's proposed 
action, large ground water systems with multiple EPTDSs may be 
permitted to sample at representative sampling locations for each 
ground water source, as long as those sites have been approved by EPA 
or the State. Samples at ground water locations will be collected twice 
during a designated consecutive 12-month period. Samples at locations 
that are fed in whole or part by a surface water or GWUDI source will 
be collected quarterly during a designated consecutive 12-month period. 
Large system schedules (year and months of monitoring) will be 
determined by EPA in conjunction with the States (as described in 
section III.G.2 of today's action). The Agency will schedule and 
coordinate small system monitoring, working closely with partnering 
States. State Monitoring Plans will provide a venue for States to 
review and revise the initial sampling schedules that EPA proposes. The 
11 proposed List 1 contaminants to be monitored under Assessment 
Monitoring are:

1,3-dinitrobenzene
2,2',4,4'-tetrabromodiphenyl ether (BDE-47)
2,2',4,4',5-pentabromodiphenyl ether (BDE-99)
2,2',4,4',5,5'-hexabromobiphenyl (245-HBB)
2,2',4,4',5,5'-hexabromodiphenyl ether (BDE-153)
2,2',4,4',6-pentabromodiphenyl ether (BDE-100)
2,4,6-trinitrotoluene (TNT)
Dimethoate
Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)
Perchlorate
Terbufos sulfone
2. Screening Survey
    Sampling under the Screening Survey for List 2 contaminants will be 
conducted from July 2007 through June 2009 by all PWSs serving more 
than 100,000 people, and by a stratified random sample of 800 PWSs 
serving 100,000 or fewer people. Samples collected at EPTDSs will be 
analyzed for the 15 contaminants listed below. Because the nitrosamine 
NDMA can be formed in chlorinated or chloraminated water as a DBP, the 
concentration may increase as the water travels through the 
distribution system (Mitch and Sedlak, 2002). Thus, EPA proposes an 
additional sampling location for the nitrosamines at the DSMRT sampling 
point defined under the Stage 1 DBPR for each treatment plant that is 
required to sample for DBPs. For plants that are not required to 
monitor for DBPs either because the water is not chemically disinfected 
or because the water is sold directly to another water system, the 
sampling location for the nitrosamines will be at the EPTDS; no DSMRT 
sample will be required. Samples at ground water locations will be 
collected twice during a designated consecutive 12-month period. 
Samples at locations that are fed in whole or part by a surface water 
or GWUDI source will be collected quarterly during a designated 
consecutive 12-month period. The 15 proposed List 2 contaminants to be 
monitored under the Screening Survey are:

Acetochlor
Acetochlor ESA
Acetochlor OA
Alachlor
Alachlor ESA
Alachlor OA
Metolachlor
Metolachlor ESA
Metolachlor OA
N-nitroso-diethylamine (NDEA)
N-nitroso-dimethylamine (NDMA)
N-nitroso-di-n-butylamine (NDBA)
N-nitroso-di-n-propylamine (NDPA)
N-nitroso-methylethylamine (NMEA)
N-nitroso-pyrrolidine (NPYR)

    A summary of the estimated number of systems to monitor under each 
UCMR 2 component is listed in Exhibit 11.

                            Exhibit 11.-- Systems To Participate in UCMR 2 Monitoring
----------------------------------------------------------------------------------------------------------------
                                     Assessment  monitoring      Screening  survey     Pre-screen
                                ---------------------------------------------------     testing
          System size                                                              -----------------  Total \2\
                                 List 1  (July 2007-June 2010)  List 2 (July 2007-    List 3 (TBD
                                                                    June 2009)            \1\)
----------------------------------------------------------------------------------------------------------------
Small Systems:
    25-10,000..................  800 selected systems.........  480 selected        TBD............        1,280
                                                                 systems
                                                                 (different than
                                                                 those for List 1).
Large Systems:
    10,001-100,000.............  All (~2,788).................  320 selected        TBD............       ~2,788
                                                                 systems.
    100,001 and over...........  All (~322)...................  All (~322)........  TBD............         ~322
                                --------------------------------
        Total..................  ~3,910.......................  ~1,122............  TBD............      ~4,390
----------------------------------------------------------------------------------------------------------------
\1\ TBD = To be determined
\2\ Totals are not additive for large systems because all large systems conduct Assessment Monitoring, and a
  subset of these will also conduct Screening Survey monitoring.


[[Page 49121]]

IV. Cost and Benefits of Today's Proposed Action

    In today's action, EPA proposes a new set of contaminants for 
monitoring in the second five-year UCMR monitoring cycle. In addition, 
UCMR 2 makes some modifications to the rule design. UCMR 2 Assessment 
Monitoring (for List 1 contaminants) will be conducted from July 2007 
through June 2010 by 800 systems serving 10,000 or fewer, and by all 
systems serving more than 10,000 people. It is assumed for this cost 
estimation that one-third of systems will monitor during each of the 
three Assessment Monitoring years. The Screening Survey for List 2 
contaminants will be conducted from July 2007 through June 2009 by 800 
systems serving 100,000 or fewer, and all systems serving more than 
100,000 (approximately 320 systems). Small systems (those serving 
10,000 or fewer people) will not be subject to more than one component 
of UCMR 2 monitoring.
    Labor costs pertain to systems, States, and EPA. They include 
activities such as reading the regulation, notifying systems selected 
to participate, sample collection, data review, reporting, and record 
keeping. Non-labor costs will be incurred primarily by EPA and by large 
PWSs. They include the cost of shipping samples to laboratories for 
testing and the cost of the actual laboratory analyses.
    In today's action, EPA proposes nine analytical methods to monitor 
for 26 new UCMR contaminants (including four method options for 
perchlorate). Estimated system and EPA costs are based on the 
analytical costs for these methods. With the exception of Method 525.2, 
these methods are comparatively new and will not coincide with other 
compliance monitoring (e.g., no cost savings for coincident monitoring 
can be realized). Laboratory analysis and shipping of samples account 
for approximately 73 percent of the national cost for UCMR 2 
implementation. These costs are calculated as follows: The number of 
systems, multiplied by the number of sampling locations, multiplied by 
the sampling frequency, multiplied by the cost of laboratory analysis. 
Under UCMR 2, surface water (and GWUDI) sampling points will be 
monitored four times during the applicable year of monitoring, and 
ground water sampling points will be monitored twice during the 
applicable year of monitoring. Screening Survey systems that are 
required to monitor for DBPs will be required to sample for 
nitrosamines at one distribution system sampling point per treatment 
plant (i.e., at the DSMRT), as well as their EPTDS sampling locations. 
EPA estimates of laboratory fees are based on consultations with 
national drinking water laboratories and the costs of analytical 
methods similar to those proposed in today's action, unit costs are as 
follows:

------------------------------------------------------------------------
 
------------------------------------------------------------------------
Assessment Monitoring (List 1):
    GC/MS (for 7 contaminants)...................................   $225
    Perchlorate (for 1 contaminant)..............................    150
    Explosives (for 3 contaminants)..............................    225
                                                                  ------
        Total....................................................    600
Screening Survey (List 2):
    Nitrosamines (for 6 contaminants)............................    300
    Acetanilide degradates (for 6 contaminants)..................    350
    Acetanilide parents (for 3 contaminants).....................    125
                                                                  ------
        Total....................................................    775
------------------------------------------------------------------------

    Shipping is added to the calculated costs to derive the total 
direct analytical non-labor costs. Estimated shipping costs were based 
on the average cost of shipping of a 15-pound package.
    Additional changes to the rule are expected to affect costs to 
small systems as compared to costs under UCMR 1.
     There will be no ``Index System'' component to the UCMR 2 
program. Under UCMR 1, samples were taken from a group of 30 small 
Index Systems during all five years of the monitoring cycle to assess 
any trends in temporal occurrence, other data variability, or program 
problems. Based on its experience with UCMR 1, EPA is not proposing 
Index System monitoring for UCMR 2.
     Small systems will only be involved in one component of 
monitoring during the five-year cycle. Since there will be a greater 
number of systems involved in the program, less monitoring will be 
required of each participating system, thus reducing the average cost 
per small system.
    In preparing the UCMR 2 information collection request (ICR), EPA 
relied on standard assumptions and data sources used in the preparation 
of other drinking water program ICRs. These include the PWS inventory, 
number of sampling points per system, and labor rates. EPA expects that 
States will incur only labor costs associated with UCMR 2 
implementation. State costs were estimated using the relevant modules 
of the State Resource Model that was recently developed by the 
Association of State Drinking Water Administrators (ASDWA) in 
conjunction with EPA (ASDWA, 2003) to help States forecast resource 
needs. Model estimates were adjusted to account for actual levels of 
State participation under UCMR 1. Because State participation is 
determined through the PAs, level of effort will vary across States and 
depend on their individual agreements with EPA.
    Over the UCMR implementation period of 2007-2011, EPA estimates 
that nationwide, the average annual cost of UCMR 2 is approximately 
$8.42 million. These total estimated annual costs (labor and non-labor) 
are incurred as follows:

------------------------------------------------------------------------
                                                         Average annual
                                                          cost for all
                      Respondent                          respondents
                                                          (2007-2011)
                                                           (millions)
------------------------------------------------------------------------
Small Systems (25-10,000), including labor only (non-              $0.05
 labor costs are paid for by EPA)....................
Large Systems (10,001-100,000), including labor and                 4.03
 non-labor costs.....................................
Very Large Systems (100,001 and greater), including                 1.53
 labor and non-labor costs...........................

[[Page 49122]]

 
States, including labor costs related to                            0.49
 implementation coordination.........................
EPA, including labor for implementation coordination                2.32
 and non-labor for small system testing..............
======================================================
 
Under Executive Order 12866, [58 FR 51735, (October
 4, 1993)] the Agency must determine whether a
 regulatory action is ``significant'' and therefore
 subject to Office of Management and Budget (OMB)
 review and the requirements of the Executive Order.
 The Order defines ``significant regulatory action''
 as one that is likely to result in a rule that may:
(1) Have an annual effect on the economy of $100
 million or more or adversely affect in a material
 way the economy, a sector of the economy,
 productivity, competition, jobs, the environment,
 public health or safety, or State, local, or Tribal
 governments or communities;
(2) Create a serious inconsistency or otherwise
 interfere with an action taken or planned by another
 agency;
(3) Materially alter the budgetary impact of
 entitlements, grants, user fees, or loan programs or
 the rights and obligations of recipients thereof; or
(4) Raise novel legal or policy issues arising out of
 legal mandates, the President's priorities, or the
 principles set forth in the Executive Order.
It has been determined that this rule is not a
 ``significant regulatory action'' under the terms of
 Executive Order 12866 and is therefore not subject
 to OMB review.
The information collection requirements in this
 proposed rule have been submitted for approval to
 the OMB under the Paperwork Reduction Act, 44 U.S.C.
 3501 et seq. The ICR document prepared by EPA has
 been assigned EPA ICR number of 2192.01.
The information to be collected under today's
 proposed rule fulfills the statutory requirements of
 section 1445(a)(2) of SDWA, as amended in 1996. The
 data to be collected will describe the source of the
 water, location, and test results for samples taken
 from PWSs. The concentrations of any identified UCMR
 contaminants will be evaluated regarding health
 effects and will be considered for future regulation
 accordingly. Reporting is mandatory. The data are
 not subject to confidentiality protection.
The annual burden and cost estimates described below
 are for the implementation assumptions described in
 section IV, Cost and Benefits of the Rule, of
 today's proposed action. Respondents to the UCMR 2
 will include 1,280 small water systems (800 for
 Assessment Monitoring, and 480 for Screening Survey
 monitoring), the 3,110 large PWSs, and the 56 States
 and Primacy agencies (4,446 total respondents). The
 frequency of response varies across respondents and
 years. System costs (particularly laboratory
 analytical costs) vary depending on the number of
 sampling locations. Most Assessment Monitoring
 systems will conduct sampling evenly across July
 2007-June 2010 (i.e., one-third in each of the 3
 consecutive 12-month periods). Because the
 applicable ICR period is 2007-2009, there is one-
 half year of Assessment Monitoring activity (i.e.,
 January through June of 2010) that is not captured
 in the ICR estimates.
Small systems (those serving 10,000 or fewer) that
 are selected for UCMR 2 monitoring will sample an
 average of 2.2 times per system (i.e., number of
 responses per system) across the three-year ICR
 period of 2007-2009. The average burden per response
 for small systems is estimated to be 3.1 hours.
 Large systems (those serving 10,001 to 100,000
 people) and very large systems (those serving more
 than 100,000 people) will sample and report an
 average of 2.5 and 3.6 times per system,
 respectively, across the three-year ICR period of
 2007-2009. The average burden per response for large
 and very large systems are estimated to be 8.9 and
 12.9 hours, respectively. The larger burden per
 response for the very large systems reflects the
 fact that these systems typically have more sampling
 locations than large systems. States are assumed to
 have an average of 1.0 response per year, related to
 coordination with EPA and systems, with an average
 burden per response of 203.2 hours. In aggregate,
 during the ICR period of 2007-2009, the average
 response (e.g., responses from systems and States)
 is associated with a burden of 10.7 hours, with a
 labor plus non-labor cost of $1,609 per response.
The annual average per respondent burden hours and
 costs for the ICR period of 2007-2009 are: Small
 systems--2.3 hour burden at $57 for labor; large
 systems--7.5 hours at $204 for labor, and $1,894 for
 analytical costs; very large systems--15.6 hours at
 $512 for labor, and $7,392 for analytical costs; and
 States--203.2 hours at $11,107 for labor. Annual
 average burden and cost per respondent (including
 both systems and States) is estimated to be 9.02
 hours, with a labor plus non-labor cost of $1,355
 per respondent (note that small systems do not pay
 for testing costs, so they only incur labor costs).
The Agency estimates the annual burden to EPA for
 proposed UCMR program activities during the ICR
 years of 2007-2009 to be approximately 9,533 hours,
 at an annual labor cost of $0.60 million. EPA's
 annual non-labor costs

[[Page 49123]]

are estimated to be $2.8 million. EPA's non-labor costs are primarily
labor cost).Burden means the total time, effort, or
 financial resources expended by persons to generate,
 maintain, retain, disclose or provide information to
 or for a Federal agency. This includes the time
 needed to review instructions; develop, acquire,
 install, and utilize technology and systems for the
 purposes of collecting, validating and verifying
 information, processing and maintaining information,
 and disclosing and providing information; adjust the
 existing ways to comply with any previously
 applicable instructions and requirements; train
 personnel to be able to respond to a collection of
 information; search data sources; complete and
 review the collection of information; and transmit
 or otherwise disclose the information.
An agency may not conduct or sponsor, and a person is
 not required to respond to, a collection of
 information unless it displays a currently valid OMB
 control number. The OMB control numbers for EPA's
 regulations in 40 CFR are listed in 40 CFR Part 9.
To comment on the Agency's need for this information,
 the accuracy of the provided burden estimates, and
 any suggested methods for minimizing respondent
 burden, including the use of automated collection
 techniques, EPA has established a public docket for
 this rule, which includes this ICR, under Docket ID
 No. OW-2004-0001. Submit any comments related to the
 ICR for this proposed rule to EPA and OMB. See
 ADDRESSES section at the beginning of this action
 for where to submit comments to EPA. Send comments
 to OMB at the Office of Information and Regulatory
 Affairs, Office of Management and Budget, 725 17th
 Street, NW., Washington, DC 20503, Attention: Desk
 Office for EPA. Since OMB is required to make a
 decision concerning the ICR between 30 and 60 days
 after August 22, 2005, a comment to OMB is best
 assured of having its full effect if OMB receives it
 by September 21, 2005. The final rule will respond
 to any OMB or public comments on the information
 collection requirements contained in this proposed
 action.
The Regulatory Flexibility Act (RFA) generally
 requires an agency to prepare a regulatory
 flexibility analysis of any rule subject to notice
 and comment rulemaking requirements under the
 Administrative Procedure Act or any other statute
 unless the agency certifies that the rule will not
 have a significant economic impact on a substantial
 number of small entities. Small entities include
 small businesses, small organizations, and small
 governmental jurisdictions.
The RFA provides default definitions for each type of
 small entity. Small entities are defined as: (1) A
 small business as defined by the Small Business
 Administration's (SBA) regulations at 13 CFR
 121.201; (2) a small governmental jurisdiction that
 is a government of a city, county, town, school
 district or special district with a population of
 less than 50,000; and (3) a small organization that
 is any ``not-for-profit enterprise which is
 independently owned and operated and is not dominant
 in its field.'' However, the RFA also authorizes an
 agency to use alternative definitions for each
 category of small entity, ``which are appropriate to
 the activities of the agency'' after proposing the
 alternative definition(s) in the Federal Register
 and taking comment 5 U.S.C. 601(3)-(5). In addition,
 to establish an alternative small business
 definition, agencies must consult with SBA's Chief
 Counsel for Advocacy.
For purposes of assessing the impacts of today's
 proposed rule on small entities, EPA considered
 small entities to be PWSs serving 10,000 or fewer
 people, because this is the system size specified in
 SDWA as requiring special consideration with respect
 to small system flexibility. As required by the RFA,
 EPA proposed using this alternative definition in
 the Federal Register, (63 FR 7605, February 13, 1998
 (USEPA, 1998a)), requested public comment, consulted
 with the Small Business Administration (SBA), and
 finalized the alternative definition in the Consumer
 Confidence Reports rulemaking, (63 FR 44511, August
 19, 1998 (USEPA, 1998c)). As stated in that Final
 rule, the alternative definition would be applied to
 this regulation as well.
After considering the economic impacts of today's
 proposed rule on small entities, I certify that this
 action will not have a significant economic impact
 on a substantial number of small entities. The small
 entities directly regulated by this proposed rule
 are PWSs serving 10,000 or fewer people. EPA has
 determined that the small entities subject to the
 requirements of this proposed rule are a subset of
 the small PWSs (those serving 10,000 or fewer
 people). The Agency has determined that 1,280 small
 PWSs (across Assessment Monitoring and the Screening
 Survey), or approximately 2 percent of small
 systems, will experience an impact of less than 0.6
 percent of revenues/sales; the remainder of systems
 will not be impacted.
Although this proposed rule will not have a
 significant economic impact on a substantial number
 of small entities, EPA nonetheless has tried to
 reduce the impact of this rule on small entities. To
 ensure that this proposed rule will not have a
 significant economic impact on a substantial number
 of small entities, EPA will assume all costs for
 analyses of the samples and for shipping the samples
 from these systems to the laboratories contracted by
 EPA to analyze UCMR 2 samples. EPA has set aside
 $2.0 million each year from the State Revolving Fund
 (SRF) with its authority to use SRF monies for the
 purposes of implementing this provision of SDWA.
 Thus, the costs to these small systems will be
 limited to the labor hours associated with
 collecting a sample and preparing it for shipping.
The Agency continues to be interested in the
 potential impacts of the proposed rule on small
 entities and welcomes comments on issues related to
 such impacts.
The evaluation of the overall impact on small
 systems, summarized in the preceding discussion, is
 further described as follows. EPA analyzed the
 impacts for privately-owned and publicly-owned water
 systems separately, due to the different economic
 characteristics of these ownership types. For
 publicly-owned systems, EPA used the ``revenue
 test,'' which compares annual system costs
 attributed to the rule to the system's annual
 revenues. EPA used a ``sales test'' for privately-
 owned systems, which involves the analogous
 comparison of UCMR-related costs to a privately-
 owned system's sales. EPA assumes that the
 distribution of the sample of participating small
 systems will reflect the proportions of publicly-
 and privately-owned systems in the national
 inventory. The estimated distribution of the
 representative sample, categorized by ownership
 type, source water, and system size, is presented
 below in Exhibit 12.

[[Page 49124]]

 
                                Ground Water
------------------------------------------------------------------------
500 and under........................................                102
501 to 3,300.........................................                179
3,301 to 10,000......................................                 95
                                                      ------------------
    Subtotal GW......................................                376
------------------------------------------------------
                          Surface Water (and GWUDI)
------------------------------------------------------------------------
500 and under........................................                 48
501 to 3,300.........................................                 95
3,301 to 10,000......................................                 87
                                                      ------------------
    Subtotal SW......................................                230
                                                      ==================
        Total of Small Water Systems.................                606
------------------------------------------------------------------------

    The basis for the UCMR 2 RFA certification for this proposed rule 
is as follows: For the 1,280 small water systems that will be affected, 
the average annual costs for complying with this rule represent less 
than 0.6 percent of system revenues or sales (the highest estimated 
percentage is for surface water/GWUDI systems serving 500 or fewer 
people, at 0.53 percent of its median sales). Exhibit 13 presents the 
yearly costs to small systems, and to EPA for the small system sampling 
program, along with an illustration of system participation for each 
year of the UCMR 2 program.

                                           Exhibit 13.--EPA and Small Systems Costs for Implementation UCMR 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
           Cost description                    2007               2008               2009               2010               2011              Total
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Costs to EPA for Small System Program (including Assessment Monitoring, and the Screening Survey)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               $1,747,951         $3,495,903         $2,278,325           $530,374                 $0         $8,052,553
---------------------------------------
                                   Costs to Small Systems (including Assessment Monitoring, and the Screening Survey)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 $122,838            $56,789            $37,731             $9,337                 $0           $226,695
---------------------------------------
                                                     Total Costs to EPA and Small Systems for UCMR 2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                               $1,870,789         $3,552,692         $2,316,056           $539,711                 $0         $8,279,248
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                        System Monitoring Activity Time Line \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Assessment Monitoring........  \1/3\ PWSs Sample..........  \1/3\ PWSs Sample.........  \1/3\ PWSs Sample.........  .................                800
Screening Survey.............  \1/2\ PWSs Sample..........  \1/2\ PWSs Sample.........  ..........................  .................               480
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Total number of systems is 1,280. No small system conducts both Assessment Monitoring and Screening Survey.

    System costs are attributed to the additional labor required for 
reading about their requirements, monitoring, reporting, and record 
keeping. The estimated average annual burden across the five-year UCMR 
2 implementation period of 2007-2011 is estimated to be 1.4 hours at 
$35 per small system. Average annual cost, in all cases, is less than 
0.6 percent of system revenues/sales. As required by the SDWA, the 
Agency specifically structured the rule to avoid significantly 
affecting small entities by assuming all costs for laboratory analyses, 
shipping, and quality control for small entities. As a result, EPA 
incurs the entirety of the non-labor costs associated with UCMR 2 small 
system monitoring, or 97 percent of small system testing costs. 
Exhibits 14 and 15 present the estimated economic impacts in the form 
of a revenue test for publicly-owned systems and a sales test for 
privately-owned systems, respectively.

[[Page 49125]]



                Exhibit 14.--UCMR 2 Relative Cost Analysis for Publicly-Owned Systems (2007-2011)
----------------------------------------------------------------------------------------------------------------
                                                                             Average
                                                                 Annual       annual      Average     ``Revenue
                         System size                           number of    hours per   annual cost   Test'' \1\
                                                                systems       system     per system   (percent)
                                                                impacted   (2007-2011)  (2007-2011)
----------------------------------------------------------------------------------------------------------------
                                              Ground Water Systems
----------------------------------------------------------------------------------------------------------------
500 and under...............................................           20          1.1       $26.38         0.11
501 to 3,300................................................           36          1.3        33.43         0.02
3,301 to 10,000.............................................           19          1.8        46.50         0.01
-------------------------------------------------------------
                                        Surface Water (and GWUDI) Systems
----------------------------------------------------------------------------------------------------------------
500 and under...............................................            9          2.0        47.45         0.20
501 to 3,300................................................           19          2.0        50.63         0.04
3,301 to 10,000.............................................           17          2.2        58.46        0.01
----------------------------------------------------------------------------------------------------------------
\1\ The ``Revenue Test'' was used to evaluate the economic impact of an information collection on small
  government entities (e.g., publicly-owned systems); costs are presented as a percentage of median annual
  revenue in each size category.


               Exhibit 15.--UCMR 2 Relative Cost Analysis for Privately-Owned Systems (2007-2011)
----------------------------------------------------------------------------------------------------------------
                                                                  Average annual  Average annual
                                                   Annual number     hours per       cost per     ``Sales Test''
                   System size                      of systems    system  (2007-  system  (2007-   1  (percent)
                                                     impacted          2011)           2011)
----------------------------------------------------------------------------------------------------------------
                                              Ground Water Systems
----------------------------------------------------------------------------------------------------------------
500 and under...................................             105             1.1          $26.38            0.30
501 to 3,300....................................              12             1.3           33.43            0.02
3,301 to 10,000.................................               4             1.8           46.50             .01
-------------------------------------------------
                                        Surface Water (and GWUDI) Systems
----------------------------------------------------------------------------------------------------------------
500 and under...................................              11             2.0           47.45            0.53
501 to 3,300....................................               1             2.0           50.63            0.03
3,301 to 10,000.................................               1             2.2           58.46           0.01
----------------------------------------------------------------------------------------------------------------
1 The ``Sales Test'' was used to evaluate the economic impact of an information collection on small private
  entities (e.g., privately-owned systems); costs are presented as a percentage of median annual sales in each
  size category.

D. Unfunded Mandates Reform Act

    Title II of the Unfunded Mandates Reform Act of 1995 (UMRA), Public 
Law 104-4, establishes requirements for Federal agencies to assess the 
effects of their regulatory actions on State, local, and Tribal 
governments and the private sector. Under section 202 of the UMRA, EPA 
generally must prepare a written statement, including a cost-benefit 
analysis, for proposed and final rules with ``Federal mandates'' that 
may result in expenditures to State, local, and Tribal governments, in 
the aggregate, or to the private sector, of $100 million or more in any 
1 year. Before promulgating an EPA rule for which a written statement 
is needed, section 205 of the UMRA generally requires EPA to identify 
and consider a reasonable number of regulatory alternatives and adopt 
the least costly, most cost-effective, or least burdensome alternative 
that achieves the objectives of the rule. The provisions of section 205 
do not apply when they are inconsistent with applicable law. Moreover, 
section 205 allows EPA to adopt an alternative other than the least 
costly, most cost-effective, or least burdensome alternative if the 
Administrator publishes with the final rule an explanation of why that 
alternative was not adopted. Before EPA establishes any regulatory 
requirements that may significantly or uniquely affect small 
governments, including Tribal governments, it must have developed under 
section 203 of the UMRA a small government agency plan. The plan must 
provide for notifying potentially affected small governments, enabling 
officials of affected small governments to have meaningful and timely 
input in the development of EPA regulatory proposals with significant 
Federal intergovernmental mandates, and informing, educating, and 
advising small governments on compliance with the regulatory 
requirements.
    EPA has determined that this rule does not contain a Federal 
mandate that may result in expenditures of $100 million or more for 
State, local, and tribal governments, in the aggregate, or the private 
sector in any one year. Total annual costs of today's proposed rule 
(across the implementation period of 2007-2011), for State, local, and 
Tribal governments and the private sector, are estimated to be $8.42 
million, of which EPA will pay $2.32 million, or approximately 28 
percent. Thus, today's rule is not subject to the requirements of 
sections 202 and 205 of the UMRA.
    EPA has determined that this rule contains no regulatory 
requirements that might significantly or uniquely affect small 
governments. The Agency will pay for the reasonable costs of sample 
analysis for the small PWSs required to monitor for unregulated 
contaminants under this proposed rule, including those owned and 
operated by small governments. The only costs that small systems will 
incur are those attributed to collecting the UCMR samples and packing 
them for shipping to the laboratory (EPA will pay for shipping). These 
costs are minimal. They are not significant or unique. Thus, today's 
rule is not subject to the requirements of UMRA section 203.

[[Page 49126]]

E. Executive Order 13132: Federalism

    Executive Order 13132, entitled ``Federalism'' (64 FR 43255, August 
10, 1999), requires EPA to develop an accountable process to ensure 
``meaningful and timely input by State and local officials in the 
development of regulatory policies that have federalism implications.'' 
``Policies that have federalism implications'' is defined in the 
Executive Order to include regulations that have ``substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government.''
    This proposed rule does not have Federalism implications. It will 
not have substantial direct effects on the States, on the relationship 
between the national government and the States, or on the distribution 
of power and responsibilities among the various levels of government, 
as specified in Executive Order 13132.
    The cost to State and local governments is minimal, and the rule 
does not preempt State law. Thus, Executive Order 13132 does not apply 
to this rule. In the spirit of Executive Order 13132, and consistent 
with EPA policy to promote communications between EPA and State and 
local governments, EPA specifically solicits comment on the proposed 
rule from State and local officials.

F. Executive Order 13175: Consultation and Coordination With Indian 
Tribal Governments

    Executive Order 13175, entitled ``Consultation and Coordination 
with Indian Tribal Governments'' (65 FR 67249, November 9, 2000), 
requires EPA to develop an accountable process to ensure ``meaningful 
and timely input by tribal officials in the development of regulatory 
policies that have tribal implications.''
    EPA has concluded that this proposed rule will have Tribal 
implications. However, it will neither impose substantial direct 
compliance costs on Tribal governments, nor preempt Tribal law. As 
described previously, this proposed rule requires monitoring by all 
large systems (i.e., those serving more than 10,000 people); one Tribal 
water system (the Navajo Tribal Utility Authority) has been identified 
as a large system. This proposal rule also requires monitoring by a 
nationally representative sample of small systems (i.e., those serving 
10,000 or fewer people). EPA estimates that approximately one percent 
of small Tribal systems will be selected as part of such sample.
    With regard to the single large Tribal system, EPA estimates the 
average annual cost for a large system over the five-year rule period 
to be less than $1,500. Such cost is based on a labor component 
(associated with the collection of samples) and a non-labor component 
(associated with shipping and laboratory fees) and represents less than 
0.05 percent of average revenue/sales for large systems.
    With regard to small Tribal systems that may be selected as part of 
the nationally representative sample, EPA estimates the average annual 
cost over the five-year rule period to be $35. Such cost is based on 
the labor associated with collecting a sample and preparing it for 
shipping and represents less than 0.6 percent of average revenue/sales 
for small systems. All other small-system expenses (associated with 
shipping and laboratory fees) are paid by EPA.
    EPA consulted with Tribal officials early in the process of 
developing the UCMR program to permit them to have meaningful and 
timely input into its development. In developing the original UCMR 
rule, EPA held stakeholder meetings and prepared background information 
for stakeholder review. EPA sent requests for review of stakeholder 
documents to nearly 400 Tribes, Tribal organizations, and small systems 
organizations to obtain their input. Representatives from the Indian 
Health Service (IHS) Sanitary Deficiency System (SDS) and Tribes were 
consulted regarding decisions on rule design, the design for the 
statistical selection of small systems, and potential costs.
    Tribes raised issues concerning the selection of the nationally 
representative sample of small systems, particularly the manner in 
which Tribal systems would be considered under the sample selection 
process. EPA developed the sample frame for Tribal systems and Alaska 
Native water systems in response to those concerns. EPA worked with the 
Tribes, Alaska Natives, the IHS, and the States to determine how to 
classify each Tribal system for consideration in the statistically-
based selection of the nationally representative sample of small 
systems. As a result of those discussions, small PWSs that are located 
in Indian country in each of the EPA Regions containing Indian country 
were evaluated as part of a Tribal category that receives selection 
consideration comparable to that of small systems outside of Indian 
country. Thus, Tribal systems have the same probability of being 
selected as other water systems in the stratified selection process 
that weighs systems by water source and size class by population 
served.
    Today's proposed rule, addressing the next UCMR period, maintains 
the basic program design of the original UCMR, building upon the 
structure established by the original rule for this cyclical program. 
The primary changes include: (1) Improving the design of the Screening 
Survey for List 2 contaminants to increase the statistical strength of 
the sampling results; (2) updating the lists of contaminants to be 
monitored and the analytical methods approved to conduct that 
monitoring; (3) revising the ``data elements'' required to be reported; 
and (4) revising the implementation of the monitoring program to 
reflect ``lessons learned'' during UCMR 1.
    As part of the development of this proposed rule, EPA held a public 
stakeholder meeting on October 23, 2003. This meeting was announced to 
the public in a Federal Register notice dated September 11, 2003. Prior 
to the meeting, background materials and rule development information 
were sent to specific stakeholders, including representatives from the 
Indian Health Service and the Native American Water Association.
    EPA specifically solicits additional comment on this proposed rule 
from Tribal officials.

G. Executive Order 13045: Protection of Children From Environmental 
Health and Safety Risks

    Executive Order 13045, ``Protection of Children from Environmental 
Health Risks and Safety Risks'' (62 FR 19885, April 23, 1997), applies 
to any rule that: (1) Is determined to be ``economically significant'' 
as defined under Executive Order 12866, and (2) concerns an 
environmental health or safety risk that EPA has reason to believe may 
have a disproportionate effect on children. If the regulatory action 
meets both criteria, the Agency must evaluate the environmental health 
or safety effects of the planned rule on children, and explain why the 
planned regulation is preferable to other potentially effective and 
reasonably feasible alternatives considered by the Agency.
    This proposed rule is part of the Agency's overall strategy for 
deciding whether to regulate the contaminants identified on the CCL (63 
FR 10274, March 2, 1998 (USEPA, 1998b)). The purpose of today's 
proposed rule is to ensure that EPA has data on the occurrence of 
contaminants on the CCL where those data are lacking. EPA is also 
taking steps to ensure that the Agency will have data on the health 
effects of these contaminants on

[[Page 49127]]

children through its research program. The Agency will use these data 
(both contaminant occurrence and health effects) to help decide whether 
or not to regulate any of these contaminants.
    This proposed rule is not subject to the Executive Order because it 
is not economically significant as defined in Executive Order 12866, 
and because the Agency does not have reason to believe the 
environmental health or safety risks addressed by this action present a 
disproportionate risk to children. However, given EPA's interest in 
protecting children's health, as part of the provisions in the rule 
allowing State Governors to petition EPA to add contaminants to the 
UCMR Contaminant List, EPA is specifically asking Governors to include 
any information that might be available regarding disproportional risks 
to the health or safety of children. Such information would help inform 
EPA's decision making regarding the UCMR Contaminant List.

H. Executive Order 13211: Actions That Significantly Affect Energy 
Supply, Distribution, or Use

    This rule is not subject to Executive Order 13211, ``Actions 
Concerning Regulations That Significantly Affect Energy Supply, 
Distribution, or Use'' (66 FR 28355, May 22, 2001) because it is not a 
significant regulatory action under Executive Order 12866.

I. National Technology Transfer and Advancement Act

    Section 12(d) of the National Technology Transfer and Advancement 
Act of 1995 (NTTAA), Public Law 104-113, Section 12(d) (15 U.S.C. 272 
note) directs EPA to use voluntary consensus standards in its 
regulatory activities unless to do so would be inconsistent with 
applicable law or otherwise impractical. Voluntary consensus standards 
are technical standards (e.g., materials specifications, test methods, 
sampling procedures, and business practices) that are developed or 
adopted by voluntary consensus standards bodies. The NTTAA directs EPA 
to provide Congress, through OMB, explanations when the Agency decides 
not to use available and applicable voluntary consensus standards.
    This proposed rulemaking involves technical standards. Therefore, 
the Agency conducted a search to identify potentially applicable 
voluntary consensus standards. In preparing this proposed action, EPA 
searched for consensus methods published by the three major voluntary 
consensus method organizations, Standard Methods, Association of 
Analytical Communities International, and American Society for Testing 
and Materials, that would be acceptable for compliance determinations 
under SDWA for the Unregulated Contaminant Monitoring List. However, 
EPA identified no such standards. For those parameters included in this 
proposed action, EPA was unable to use methods from either EPA or 
voluntary consensus method organizations that were applicable to the 
monitoring required. Therefore, EPA proposes to use the methods 
development that the Agency conducted (described in section III.B), 
which was necessary to establish acceptable methods for the 
determination of these UCMR 2 parameters.

J. Executive Order 12898: Federal Actions To Address Environmental 
Justice in Minority Populations and Low-Income Populations

    Executive Order 12898, ``Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations'' (February 
11, 1994), focuses Federal attention on the environmental and human 
health conditions of minority and low-income populations with the goal 
of achieving environmental protection for all communities.
    By seeking to identify unregulated contaminants that may pose 
health risks via drinking water from all PWSs, UCMR furthers the 
protection of public health for all citizens, including minority and 
low-income populations using public water supplies. Using a 
statistically-derived set of systems for the nationally representative 
sample that is population-weighted within each system size category in 
each State, the proposed rule ensures that no group within the 
population is under-represented.

VII. Public Involvement in Regulation Development

    EPA's Office of Ground Water and Drinking Water has developed a 
process for stakeholder involvement in its regulatory activities for 
the purpose of providing early input to regulation development. When 
designing and developing the UCMR program, in the late 1990s, EPA held 
meetings for developing the CCL, establishing the information 
requirements of the NCOD, and selecting priority contaminants for 
monitoring. During the initial development of the UCMR program, 
stakeholders, including PWSs, States, industry, and other organizations 
attended meetings to discuss the UCMR. Seventeen other meetings were 
held specifically concerning UCMR development. For a description of 
public involvement activities related to the UCMR, please see the 
discussion in the September 1999 UCMR Final Rule Federal Register at 64 
FR 50556 (USEPA, 1999c).
    Specific to the development of UCMR 2, a stakeholder meeting was 
held on October 29, 2003, in Washington, DC. There were 25 attendees, 
representing State agencies, federal agencies, laboratories, PWSs, and 
drinking water associations. The topics of presentations and 
discussions included: Rationale for selecting a new list of proposed 
contaminants; analytical methods to be used in measuring these 
contaminants; sampling design, particularly for the Screening Survey 
monitoring; procedure for determining LCMRLs; validation of laboratory 
performance at or below the MRL; revisions to data elements; and other 
proposed revisions based on lessons learned during implementation of 
UCMR 1.

VIII. References

    Agency for Toxic Substances and Disease Registry (ATSDR). 1989. 
Toxicological Profile for N-Nitrosodimethylamine. Atlanta, GA: 
Agency for Toxic Substances and Disease Registry, Public Health 
Service, U.S. Department of Health and Human Services. Available on 
the Internet at: http://www.atsdr.cdc.gov/toxprofiles/tp141.pdf.
    ATSDR. 1995a. Toxicological Profile for 1,3-Dinitrobenzene and 
1,3,5-Trinitrobenzene. Available on the Internet at: http://www.atsdr.cdc.gov/toxprofiles/tp74.html.
    ATSDR. 1995b. Toxicological Profile for RDX. Available on the 
Internet at: http://www.atsdr.cdc.gov/toxprofiles/tp78.html.
    ATSDR. 1995c. Toxicological Profile for 2,4,6-Trinitrotoluene. 
Available on the Internet at: http://www.atsdr.cdc.gov/toxprofiles/tp81.html.
    ATSDR. 2002. Toxicological Profile for Polybrominated Biphenyls 
and Polybrominated Diphenyl Ethers (PBBs AND PBDEs)--Draft for 
Public Comment. September 2002. Available on the Internet at: http://www.atsdr.cdc.gov/toxprofiles/tp68.html.
    Association of State Drinking Water Administrators (ASDWA). 
2003. Public Health Protection Threatened by Inadequate Resources 
for State Drinking Water Programs--An Analysis of State Drinking 
Water Programs Resources, Needs, and Barriers. April 2003. Available 
on the Internet at: http://www.asdwa.org/.
    Burrows, W. D. 1982. Tertiary treatment of effluent from Holston 
AAP industrial liquid waste treatment facility I. Batch carbon 
adsorption studies: TNT, RDX, HMX, TAX, and SEX. Technical Report 
8207. Document no. ADA121244. U.S. Army Armament Research and 
Development Command, NJ.
    California Department of Health Services (CADHS). 2002. Studies 
on the Occurrence of NDMA in Drinking Water. Available on the 
Internet at: http://www.dhs.ca.gov/ps/ddwem/chemicals/NDMA/studies.htm.

[[Page 49128]]

    California Environmental Protection Agency (CAEPA). 2002. Draft 
Groundwater Information Sheet: N-Nitrosodimethylamine (NDMA). 
Prepared By: John Borkovitch, R.G., Revised: October 23, 2002. 
Available on the Internet at: http://www.swrcb.ca.gov/gama/docs/ndma_oct2002_rev3.pdf.
    Choi, J., S.E. Duirk, and R.L. Valentine. 2002. Mechanistic 
studies of N-nitrosodimethylamine (NDMA) formation in chlorinated 
drinking water. Journal of Environmental Monitoring. Vol. 4, No. 2. 
pp. 249-52.
    Choi, J., and R.L. Valentine. 2002a. Formation of N-
nitrosodimethylamine (NDMA) from reaction of monochloramine: a new 
disinfection by-product. Water Research. Vol. 36, No. 4. pp. 817-
824.
    Choi, J., and R.L. Valentine. 2002b. A kinetic model of N-
nitrosodimethylamine (NDMA) formation during water chlorination/
chloramination. Water Science and Technology. Vol. 46, No. 3. pp. 
65-71.
    Darnerud, P.O., G.S. Erickson, T. Johannesson, P.B. Larson, and 
M. Viluksela. 2001. Polybrominated Diphenyl Ethers: Occurrence, 
Dietary Exposure, and Toxicology. Environmental Health Perspectives 
Supplements. Vol. 109, No. S1. Available on the Internet at: http://ehp.niehs.nih.gov/members/2001/suppl-1/49-68darnerud/darnerud-full.html.
    Hazardous Substances Database (HSDB). 1986. Complete Record for 
Dimethoate. Available on the Internet at: http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB.
    Hites, R. 2004. Polybrominated Diphenyl Ethers in the 
Environment and in People: A Meta-Analysis of Concentration. 
Environmental Science and Technology. Vol. 38, No. 4. pp. 945-956.
    Mitch, W.A., and D.L. Sedlak. 2002. Formation of N-
Nitrosodimethylamine (NDMA) from Dimethylamine during 
Chloramination. Environmental Science and Technology. Vol. 36, No. 
4. pp. 588-595.
    Scribner, E.A., E.M. Thurman, and L.R. Zimmerman. 2000. 
``Analysis of Selected Herbicide Metabolites in Surface and Ground 
Water of the United States.'' Kolpin, D.W. (ed.), Special Issue: 
Fate and Transport of Agricultural Chemicals in the Mississippi 
River Basin: Science of the Total Environment. 248(2,3):159-168. 
Available on the Internet at: http://ks.water.usgs.gov/Kansas/pubs/reports/wrir.99-4018B.toxicss2.pdf.
    USEPA. 1994. Pesticide Tolerances for Acetochlor; Rules and 
Regulations. Federal Register. Vol. 59, No. 56. p. 13654, March 23, 
1994.
    USEPA. 1995. Method 525.2--Determination of Organic Compounds in 
Drinking Water by Liquid-Solid Extraction and Capillary Column Gas 
Chromatography/Mass Spectrometry. Available on the Internet at: 
http://www.NEMI.gov.
    USEPA. 1996a. Pesticide Tolerances for Dimethenamid. Federal 
Register. Vol. 61, No. 52. p. 10681, March 15, 1996.
    USEPA. 1996b. National Primary Drinking Water Regulations: 
Monitoring Requirements for Public Drinking Water Supplies: 
Cryptosporidium, Giardia, Viruses, Disinfection Byproducts, Water 
Treatment Plant Data and Other Information Requirements. Federal 
Register. Vol. 61, No. 94. p. 24354, May 14, 1996.
    USEPA. 1997. Announcement of the Draft Drinking Water 
Contaminant Candidate List; Notice. Federal Register. Vol. 62, No. 
193. p. 52194, October 6, 1997.
    USEPA. 1998a. National Primary Drinking Water Regulations: 
Consumer Confidence Reports; Final Rule. Federal Register. Vol. 63, 
No. 30. p. 7605, February 13, 1998.
    USEPA. 1998b. Announcement of the Drinking Water Contaminant 
Candidate List; Notice. Federal Register. Vol. 63, No. 40. p. 10274, 
March 2, 1998.
    USEPA. 1998c. National Primary Drinking Water Regulations: 
Consumer Confidence Reports. Federal Register. Vol. 63, No. 160. p. 
44511, August 19, 1998.
    USEPA. 1999a. Federal Facilities Forum Issue: Field Sampling and 
Selecting On-site Analytical Methods for Explosives in Water. Office 
of Research and Development, Office of Solid Waste and Emergency 
Response. Prepared by A.B. Crickett, H.D. Craig, and T.F. Jenkins. 
EPA 600-S-99-002. May 1999. Available on the Internet at: http://www.epa.gov/tio/tsp/download/water.pdf.
    USEPA. 1999b. Human Health Risk Assessment: Terbufos. Office of 
Prevention, Pesticides and Toxic Substances. September 2, 1999. 
Available on the Internet at: http://www.epa.gov/pesticides/op/terbufos/_revrisk.pdf.
    USEPA. 1999c. Revisions to the Unregulated Contaminant 
Monitoring Regulation for Public Water Systems; Final Rule. Federal 
Register. Vol. 64, No. 180. p. 50556, September 17, 1999.
    USEPA. 1999d. Dimethoate Revised Risk Assessment. Office of 
Prevention, Pesticides and Toxic Substances. December 16, 1999. 
Available on the Internet at: http://www.epa.gov/pesticides/op/dimethoate/hedrra.pdf.
    USEPA. 1999e. EPA Method 314.0--Determination of Perchlorate in 
Drinking Water Using Ion Chromatography. Available on the Internet 
at: http://www.epa.gov/safewater/methods/sourcalt.html.
    USEPA. 1999f. Revised Chapter for Dimethoate RED. Available on 
the Internet at: http://www.epa.gov/pesticides/op/dimethoate/efedrra.pdf.
    USEPA. 2000a. Unregulated Contaminant Monitoring Regulation for 
Public Water Systems: Analytical Methods for Perchlorate and 
Acetochlor; Announcement of Laboratory Approval and Performance 
Testing (PT) Program for the Analysis of Perchlorate; Final Rule and 
Proposed Rule. Federal Register. Vol. 65, No. 42. p. 11372, March 2, 
2000.
    USEPA. 2000b. Science Policy Council Handbook, Peer Review. EPA 
100-B-00-001. December 2000. Available on the Internet at: http://epa.gov/osa/spc/htm/rchandbk.pdf.
    USEPA. 2001a. Unregulated Contaminant Monitoring Regulation for 
Public Water Systems; Analytical Methods for List 2 Contaminants; 
Clarifications to the Unregulated Contaminant Monitoring Regulation. 
Federal Register. Vol. 66, No. 8. p. 2273, January 11, 2001.
    USEPA. 2001b. Unregulated Contaminant Monitoring Regulation for 
Public Water Systems; Analytical Methods of List 2 Contaminants; 
Clarifications to the Unregulated Contaminant Monitoring Regulation; 
Correction. Federal Register. Vol. 66, No. 95. p. 27215, May 16, 
2001.
    USEPA. 2001c. Statistical Design and Sample Selection for the 
UCMR 1. EPA 815-R-01-004. August 2001. Available on the Internet at: 
http://www.epa.gov/safewater/ucmr/ucmr1/pdfs/guidance_ucmr1_statistical_design.pdf.
    USEPA. 2001d. Unregulated Contaminant Monitoring Regulation for 
Public Water Systems; Amendment to the List 2 Rule and Partial Delay 
of Reporting of Monitoring Results. Federal Register. Vol. 66, No. 
171. p. 46221, September 4, 2001.
    USEPA. 2002a. 2002 Edition of the Drinking Water Standards and 
Health Advisories. EPA 822-R-02-038.
    USEPA. 2002b. Unregulated Contaminant Monitoring Regulation for 
Public Water Systems; Establishment of Reporting Date. Federal 
Register. Vol. 67, No. 48. p. 11043, March 12, 2002.
    USEPA. 2002c. EPA Dockets; EPA's New Electronic Public Docket 
and Comment System; Notice of Availability. Federal Register. Vol. 
67, No. 105. p. 38102, May 31, 2002.
    USEPA. 2002d. Unregulated Contaminant Monitoring Regulation: 
Approval of Analytical Method for Aeromonas; National Primary and 
Secondary Drinking Water Regulations: Approval of Analytical Methods 
for Chemical and Microbiological Contaminants. Federal Register. 
Vol. 67, No. 209. p. 65888, October 29, 2002.
    USEPA. 2003a. Dimethoate Summary. Office of Prevention, 
Pesticides and Toxic Substances. Last updated January 6, 2003. 
Available on the Internet at: http://www.epa.gov/pesticides/op/dimethoate/dimethsumm.htm.
    USEPA. 2003b. National Primary Drinking Water Regulations: Stage 
2 Disinfectants and Disinfection Byproducts Rule; National Primary 
and Secondary Drinking Water Regulations: Approval of Analytical 
Methods for Chemical Contaminants; Proposed Rule. Federal Register. 
Vol. 68, No. 159. p. 49547, August 18, 2003.
    USEPA. 2003c. EPA Method 529--Determination of Explosives and 
Related Compounds in Drinking Water by Solid Phase Extraction and 
Capillary Column Gas Chromatography/Mass Spectrometry (GC/MS). 
Available on the Internet at: http://www.epa.gov/nerlcwww/ordmeth.htm.
    USEPA. 2003d. USEPA Integrated Risk Information System. 
Available on the Internet at: http://www.epa.gov/iris/index.html. 
Accessed for the following contaminants: Acetochlor--CASRN 34256-82-
1; Alachlor--CASRN 15972-60-8; Dimethoate--CASRN 60-51-5; m-
Dinitrobenzene--CASRN 99-65-0; Hexahydro-1,3,5-trinitro-1,3,5-
triazine (RDX)--CASRN 121-82-4; Metolachlor--CASRN 51218-45-2; N-
Nitrosodimethylamine--CASRN 62-75-9; and, 2,4,6-Trinitrotoluene 
(TNT)--CASRN 118-96-7.
    USEPA. 2003e. UCMR 2: Contaminant Selection Rationale. Draft 
background documentation presented at the UCMR 2

[[Page 49129]]

stakeholder meeting, held on October 29, 2003 in Washington, DC.
    USEPA. 2004a. 2004 Edition of the Drinking Water Standards and 
Health Advisories. EPA 822-R-04-005.
    USEPA. 2004b. EPA Method 314.1--Determination of Perchlorate in 
Drinking Water Using Inline Column Concentration/Matrix Elimination 
Ion Chromatography with Suppressed Conductivity Detection. Available 
on the Internet at: http://www.epa.gov/safewater/methods/sourcalt.html.
    USEPA. 2004c. EPA Method 331.0--Determination of Perchlorate in 
Drinking Water by Liquid Chromatography Electrospray Ionization Mass 
Spectrometry. EPA 815-R-05-007. January 2005. Available on the 
Internet at: http://www.epa.gov/safewater/methods/sourcalt.html.
    USEPA. 2004d. EPA Method 332.0--Determination of Perchlorate in 
Drinking Water Using Ion Chromatography with Suppressed Conductivity 
and Electrospray Ionization Mass Spectrometry. Available on the 
Internet at: http://www.epa.gov/nerlcwww/ordmeth.htm.
    USEPA. 2004e. EPA Method 521--Determination of Nitrosamines in 
Drinking Water by Solid Phase Extraction and Capillary Column Gas 
Chromatography with Large Volume Injection and Chemical Ionization 
Tandem Mass Spectrometry (MS/MS). Available on the Internet at: 
http://www.epa.gov/nerlcwww/ordmeth.htm.
    USEPA. 2004f. EPA Method 527--Determination of Selected 
Pesticides and Flame Retardants in Drinking Water by Solid Phase 
Extraction and Capillary Column Gas Chromatography/Mass Spectrometry 
(GC/MS). EPA 815-R-05-005. April 2005. Available on the Internet at: 
http://www.epa.gov/safewater/methods/sourcalt.html.
    USEPA. 2004g. EPA Method 535, Revision 1.1--Measurement of 
Chloroacetanilide and Other Acetamide Herbicide Degradates in 
Drinking Water by Solid Phase Extraction and Liquid Chromatography/
Tandem Mass Spectrometry (LC/MS/MS). Available on the Internet at: 
http://www.epa.gov/nerlcwww/ordmeth.htm.
    USEPA. 2004h. Estimating Potency Scores: An Exercise. Office of 
Science and Technology, Health and Ecological Criteria Division. 
Draft, June 29, 2004.
    USEPA. 2004i. Evaluation of the Lowest Concentration Minimum 
Reporting Level (LCMRL) and the Minimum Reporting Level (MRL) 
Primary Analyte Analysis. October 2004.
    USEPA. 2004j. Statistical Protocol for the Determination of the 
Single-Laboratory Lowest Concentration Minimum Reporting Level 
(LCMRL) and Validation of the Minimum Reporting Level (MRL). EPA 
815-R-05-006.
    USEPA. 2004k. UCMR 2 Laboratory Approval Requirement and 
Information Document. Available on the Internet at: http://www.epa.gov/safewater/ucmr/ucmr2/index.html.
    USEPA. 2005. Drinking Water Candidate Contaminant List 2; Final 
Notice. Federal Register. Vol. 70, No. 36. p. 9071, February 24, 
2005.

List of Subjects in 40 CFR Part 141

    Environmental protection, Chemicals, Indians-lands, 
Intergovernmental relations, Radiation protection, Reporting and record 
keeping requirements, Water supply.

    Dated: August 12, 2005.
Stephen L. Johnson,
Administrator.

    For the reasons set out in the preamble, title 40, chapter 1 of the 
Code of Federal Regulations is proposed to be amended as follows:

PART 141--NATIONAL PRIMARY DRINKING WATER REGULATIONS

    1. The authority citation for part 141 continues to read as 
follows:

    Authority: 42 U.S.C. 300f, 300g-1, 300g-2, 300g-3, 300g-4, 300g-
5, 300g-6, 300j-4, 300j-9, and 300j-11.

Subpart C--[Amended]

    2. Section 141.24 is amended by revising paragraphs (h) 
introductory text and (h)(7)(v) to read as follows:


Sec.  141.24  Organic chemical, sampling and analytical requirements.

* * * * *
    (h) Analysis of the contaminants listed in Sec.  141.61(c) for the 
purposes of determining compliance with the maximum contaminant level 
shall be conducted as follows:
* * * * *
    (7) * * *
    (v) If the monitoring results in detection of one or more of 
certain related contaminants (heptachlor and heptachlor epoxide), then 
subsequent monitoring shall analyze for all related contaminants.
* * * * *

Subpart D--[Amended]

    3. Section 141.35 is revised to read as follows:


Sec.  141.35  Reporting for unregulated contaminant monitoring.

    (a) General applicability. This section applies to any owner or 
operator of a public water system (PWS) required to monitor for 
unregulated contaminants under Sec.  141.40(a): Such owner or operator 
is referred to as ``you.'' This section specifies the information that 
must be reported to EPA prior to the commencement of monitoring, and 
describes the process for reporting monitoring results to EPA. For the 
purposes of this section, PWS ``population served'' includes the sum of 
the retail population served directly by the PWS plus the population 
served by any consecutive system(s) receiving all or part of its 
finished water from that PWS. For purposes of this section, the term 
``State'' refers to the State or Tribal government entity that has 
jurisdiction over your PWS even if that government does not have 
primary enforcement responsibility for PWSs under the Safe Drinking 
Water Act. For purposes of this section, the term ``PWS Official'' 
refers to the person at your PWS who is able to function as the 
official spokesperson for the system's Unregulated Contaminant 
Monitoring Regulation (UCMR) activities; and the term ``PWS Technical 
Contact'' refers to the person at your PWS who is responsible for the 
technical aspects of your UCMR activities, such as details concerning 
sampling and reporting.
    (b) Reporting by all systems. You must meet the reporting 
requirements of this paragraph if you meet the applicability criteria 
in Sec.  141.40(a)(1) and (2).
    (1) Where to submit UCMR reporting requirement information. Some of 
your reporting requirements are to be fulfilled electronically, and 
others by mail. Information that must be submitted using EPA's 
electronic data reporting system can be accessed through: http://www.epa.gov/safewater/ucmr/ucmr2/reporting.html. Documentation that is 
required to be mailed can be submitted either: to UCMR Sampling 
Coordinator, USEPA, Technical Support Center, 26 West Martin Luther 
King Drive (MS 140), Cincinnati, OH 45268; or by e-mail at [email protected]; or by fax at (513) 569-7191. In 
addition, you must notify the public of the monitoring results as 
provided in Subpart O (Consumer Confidence Reports) and Subpart Q 
(Public Notification) of this part.
    (2) Contacting EPA if your system does not meet applicability 
criteria or has status change. If you have received a letter from EPA 
concerning your required monitoring and your system does not meet the 
applicability criteria for UCMR established in Sec.  141.40(a)(1) and 
(2), or if a change occurs at your system that may affect your 
requirements under UCMR as defined in Sec.  141.40(a)(3)-(5), you must 
fax, mail, or e-mail a letter to EPA, as specified in paragraph (b)(1) 
of this section. The letter must be from your PWS Official and must 
include an explanation as to why the UCMR requirements are not 
applicable to your PWS, or have changed for your PWS, along with the 
appropriate contact information. EPA will make an applicability 
determination based on your letter and in consultation with the State 
when necessary. If you meet the applicability

[[Page 49130]]

requirements specified in Sec.  141.40(a)(1) and (2), you are subject 
to UCMR requirements until or unless you receive a letter from EPA 
agreeing that you do not meet the applicability criteria.
    (c) Reporting by large systems. If you serve a population of more 
than 10,000 people, and meet the applicability criteria in Sec.  
141.40(a)(1) and (2)(i), you must meet the reporting requirements in 
paragraph (c)(1) through (8) of this section.
    (1) Contact information. You must provide contact information by 
[DATE 90 DAYS AFTER PUBLICATION OF THE FINAL RULE], and provide updates 
within 30 days if this information changes. The contact information 
must be submitted using EPA's electronic data reporting system, as 
specified in paragraph (b)(1) of this section, and include the name, 
affiliation, mailing address, phone number, fax number, and e-mail 
address for your PWS Technical Contact and your PWS Official.
    (2) Sampling location and inventory information. You must provide 
your sampling location and inventory information by [DATE 210 DAYS 
AFTER PUBLICATION OF THE FINAL RULE] using EPA's electronic data 
reporting system. You must submit the following information for each 
sampling location, or for each approved representative sampling 
location (as specified in paragraph (c)(3) of this section regarding 
representative sampling locations): PWS identification (PWSID) code; 
PWS facility identification code; sampling point identification code; 
sampling point type identification code; sampling location water type, 
which are defined in Table 1, paragraph (e) of this section. If this 
information changes, you must report updates to EPA's electronic data 
reporting system within 30 days of the change.
    (3) Proposed ground water representative sampling locations. Some 
systems that use ground water as a source and have multiple entry 
points to the distribution system (EPTDSs) may propose monitoring at 
representative entry point(s), rather than monitor at every EPTDS, as 
follows:
    (i) Qualifications. Large PWSs that have State-approved alternate 
EPTDS sampling locations, as provided for under Sec. Sec.  
141.23(a)(1), 141.24(f)(1), and 141.24(h)(1), may submit a copy of 
documentation from their State that approves their alternative sampling 
plan for EPTDSs. PWSs that do not have an approved alternative EPTDS 
sampling plan may submit a proposal to sample at representative 
EPTDS(s) rather than at each individual EPTDS if: they use ground water 
as a source; all of their well sources have either the same treatment 
or no treatment; and they have an EPTDS for each well within a well 
field (resulting in multiple EPTDSs from the same source, such as an 
aquifer). You must submit a copy of the existing alternate EPTDS 
sampling plan or your representative well proposal, as appropriate, by 
[INSERT DATE 120 DAYS AFTER PUBLICATION OF THE FINAL RULE].
    (ii) Demonstration. If you are submitting a proposal to sample at 
representative EPTDS(s) rather than at each individual EPTDS, you must 
demonstrate that any EPTDS that you select as representative of the 
ground water you supply from multiple wells is associated with a well 
that draws from the same aquifer as the wells it will represent. You 
must submit the following information for each proposed representative 
sampling location: PWSID Code, PWS facility identification code, and 
sampling point identification code (as defined in Table 1, paragraph 
(e) of this section). You must also include documentation to support 
your proposal that the specified wells are representative of other 
wells. This documentation can include system-maintained well logs or 
construction drawings indicating comparable depths (relative to 
elevation datum) of screened intervals, and details of well casings and 
grouting; data demonstrating relative homogeneity of water quality 
constituents (e.g., pH, dissolved oxygen, conductivity, iron, 
manganese) in samples drawn from each well; and data showing that your 
wells are located in a limited geographic area (e.g., all wells within 
a 0.5 mile radius) and/or, if available, the hydrogeologic data 
indicating the time of travel separating the representative well from 
each of the individual wells it represents (e.g., all wells within a 
five-year time of travel delineation). Your proposal must be sent in 
writing to EPA, as specified in paragraph (b)(1) of this section. You 
must also provide a copy of this information to the State, unless 
otherwise directed by the State. Information about the actual or 
potential occurrence or non-occurrence of contaminants in an individual 
well, or a well's vulnerability to contamination must not be used as a 
basis for selecting a representative well.
    (iii) Approval. EPA or the State (as specified in the Partnership 
Agreement reached between the State and EPA) will review your proposal, 
coordinate any necessary changes with you, and approve the final list 
of EPTDSs where you will be required to monitor. Your plan will not be 
final until you receive written approval from EPA or the State.
    (4) Contacting EPA if your PWS has not been notified of 
requirements. If you believe you are subject to UCMR requirements, as 
defined in Sec.  141.40(a)(1) and (2)(i), and you have not been 
notified by either EPA or your State by [DATE 150 DAYS AFTER 
PUBLICATION OF THE FINAL RULE], you must send a letter to EPA, as 
specified in paragraph (b)(1) of this section. The letter must be from 
your PWS Official, and must include an explanation as to why the UCMR 
requirements are applicable to your system along with the appropriate 
contact information. A copy of the letter must also be submitted to the 
State, as directed by the State. EPA will make an applicability 
determination based on your letter, and in consultation with the State 
when necessary, and will notify you regarding your applicability status 
and required sampling schedule. However, if your PWS meets the 
applicability criteria specified in Sec.  141.40(a)(1) and (2)(i), you 
are subject to the UCMR monitoring and reporting requirements, 
regardless of whether or not you have been notified by the State or 
EPA.
    (5) Notifying EPA if your PWS cannot sample according to schedule. 
You may change you Assessment Monitoring (List 1) or Screening Survey 
(List 2) schedule up to [DATE 210 DAYS AFTER PUBLICATION OF THE FINAL 
RULE] using EPA's electronic data reporting system, as specified in 
paragraph (b)(1) of this section. After these dates have passed, if 
your PWS cannot sample according to your assigned sampling schedule 
(e.g., because of budget constraints, or if a sampling location will be 
closed during scheduled month of monitoring), you must fax, mail, or e-
mail a letter to EPA, as specified in paragraph (b)(1) of this section, 
prior to the scheduled sampling date. You must include an explanation 
of why the samples cannot be taken according to the assigned schedule, 
and requesting an alternative schedule. You are subject to your 
assigned UCMR sampling schedule or the schedule that you revised on or 
before [DATE 210 DAYS AFTER PUBLICATION OF THE FINAL RULE], until and 
unless you receive a letter from EPA specifying a new schedule.
    (6) Reporting monitoring results. For each sample, you must report 
the information specified in Table 1 of paragraph (e) of this section, 
using EPA's electronic data reporting system. If you are conducting 
Assessment Monitoring, you must include data elements 1 through 5, and 
7 through 15;

[[Page 49131]]

and if you are conducting Screening Survey, you must include elements 1 
through 15. You also must report any changes made to data elements 1 
through 6 to EPA, in writing, explaining the nature and purpose of the 
proposed change, as specified in paragraph (b)(1) of this section.
    (i) Electronic reporting system. You are responsible for ensuring 
that the laboratory conducting unregulated contaminant analysis posts 
the analytical results to EPA's electronic reporting system. You are 
also responsible for reviewing, approving, and submitting those results 
to EPA.
    (ii) Reporting schedule. You must ensure that your laboratory posts 
the data in EPA's electronic data reporting system within 120 days from 
the sample collection date (sample collection must occur as specified 
in Sec.  141.40(a)(4)). You have 60 days from when the laboratory posts 
the data in EPA's electronic data reporting system to review, approve, 
and submit the data to the State and EPA, at the Web address specified 
in paragraph (b)(1) of this section. If you do not take action on the 
data within 60 days of the laboratory's posting to the electronic 
reporting system, the data will be considered approved by you, and 
available for EPA and State review.
    (7) Only one set of results accepted. If you report more than one 
set of valid results for the same sampling location and the same 
sampling event (for example, because you have had more than one 
laboratory analyze replicate samples collected under Sec.  
141.40(a)(5), or because you have collected multiple samples during a 
single monitoring event at the same sampling location), EPA will use 
the highest of the reported values as the official result.
    (8) No reporting of previously collected data. You cannot report 
previously collected data to meet the testing and reporting 
requirements for the contaminants listed in Sec.  141.40(a)(3). All 
analyses must be performed by laboratories approved by EPA to perform 
UCMR analyses using the analytical methods specified in Table 1 of 
Sec.  141.40(a)(3) and using samples collected according to the 
approved monitoring plan. Such requirements preclude the possibility of 
``grandfathering'' previously collected data.
    (d) Reporting by small systems. If you serve a population of 10,000 
or fewer people, and you are notified that you have been selected for 
UCMR monitoring, your reporting requirements will be specified within 
the materials that EPA sends you, including a request for contact 
information, and a request for information associated with the sampling 
kit.
    (1) Contact information. EPA will send you a notice requesting 
contact information for key individuals at your system, including name, 
affiliation, mailing address, phone number, fax number, and e-mail 
address. These individuals include your PWS Technical Contact and your 
PWS Official. You are required to provide this information within 90 
days of receiving the notice from EPA. If this information changes, you 
also must provide updates within 30 days of the change.
    (2) Reporting sampling information. You must record data elements 
listed in Table 1 of paragraph (e) of this section, on each sample form 
and sample bottle provided to you by your UCMR Sampling Coordinator. If 
you are conducting Assessment Monitoring, you must include elements 1 
through 5, and 7; and if you are conducting Screening Survey, you must 
include elements 1 through 7. You must send this information as 
specified in the instructions of your sampling kit, which will include 
the due date and return address. You must report any changes made in 
data elements 1 through 6 by mailing or e-mailing an explanation of the 
nature and purpose of the proposed change to EPA, as specified in 
paragraph (b)(1) of this section.
    (e) Data elements. Table 1 defines the data elements that must be 
provided with UCMR sample results.

   Table 1.--Unregulated Contaminant Monitoring Reporting Requirements
------------------------------------------------------------------------
         Data element                          Definition
------------------------------------------------------------------------
1. Public Water System         The code used to identify each PWS. The
 Identification (PWSID) Code.   code begins with the standard 2-
                                character postal State abbreviation or
                                Region code; the remaining 7 numbers are
                                unique to each PWS in the State. The
                                same identification code must be used to
                                represent the PWS identification for all
                                current and future UCMR monitoring.
2. Public Water System         An identification code established by the
 Facility Identification Code.  State or, at the State's discretion, by
                                the PWS, following the format of a 5-
                                digit number unique within each PWS for
                                each applicable facility (i.e., for each
                                source of water, treatment plant,
                                distribution system, or any other
                                facility associated with water treatment
                                or delivery). The same identification
                                code must be used to represent the
                                facility identification for all current
                                and future UCMR monitoring.
3. Water Source Type.........  The type of source water that supplies a
                                water system facility. Systems must
                                report one of the following codes for
                                each sampling location:
                               SW = surface water (to be reported for
                                water facilities that are served all or
                                in part by a surface water source).
                               GW = ground water (to be reported for
                                water facilities that are served
                                entirely by a ground water source).
                               GU = ground water under the direct
                                influence of surface water (to be
                                reported for water facilities that are
                                served all or in part by ground water
                                under the direct influence of surface
                                water).
4. Sampling Point              An identification code established by the
 Identification Code.           State, or at the State's discretion, by
                                the PWS, unique within each applicable
                                facility, for each applicable sampling
                                location (i.e., entry point to the
                                distribution system or distribution
                                system sample at maximum residence
                                time). The same identification code must
                                be used to represent the sampling
                                location for all current and future UCMR
                                monitoring.
5. Sampling Point Type         An identification code corresponding to
 Identification Code.           the location of the sampling point.
                               EP = entry point to the distribution
                                system.
                               MR = distribution system sample at
                                maximum residence time.
6. Disinfectant Residual Type  The type of disinfectant used to maintain
                                a residual in the distribution system
                                for each Screening Survey sampling
                                point. To be reported by systems
                                required to conduct Screening Survey
                                monitoring. Systems must report using
                                the following codes for each Screening
                                Survey sampling location (i.e., EP, MR):
                               CL = chlorine

[[Page 49132]]

 
                               CA = chloramine
                               OT = all other types of disinfectant
                                (e.g., chlorine dioxide)
                               ND = no disinfectant used.
7. Sample Collection Date....  The date the sample is collected,
                                reported as 4-digit year, 2-digit month,
                                and 2-digit day.
8. Sample Identification Code  An alphanumeric value up to 30 characters
                                assigned by the laboratory to uniquely
                                identify containers, or groups of
                                containers, containing water samples
                                collected at the same sampling location
                                for the same sampling date.
9. Contaminant...............  The unregulated contaminant for which the
                                sample is being analyzed.
10. Analytical Method Code...  The identification code of the analytical
                                method used.
11. Sample Analysis Type.....  The type of sample collected and/or
                                prepared, as well as the fortification
                                level. Permitted values include:
                               FS = field sample; sample collected and
                                submitted for analysis under this rule.
                               LFSM = laboratory fortified sample
                                matrix; a UCMR field sample with a known
                                amount of the contaminant of interest
                                added.
                               LFSMD = laboratory fortified sample
                                matrix duplicate; duplicate of the
                                laboratory fortified sample matrix.
                               CF = concentration fortified; reported
                                with sample analysis types LFSM and
                                LFSMD, the concentration of a known
                                contaminant added to a field sample.
12. Analytical Results--Sign.  A value indicating whether the sample
                                analysis result was: (<) ``less than''
                                means the contaminant was not detected,
                                or was detected at a level below the
                                Minimum Reporting Level. (=) ``equal
                                to'' means the contaminant was detected
                                at the level reported in ``Analytical
                                Result--Value.''
13. Analytical Result--Value.  The actual numeric value of the analysis
                                for chemical and microbiological results
                                for: field samples; laboratory fortified
                                matrix samples; laboratory fortified
                                sample matrix duplicates; and
                                concentration fortified.
14. Laboratory Identification  The code, assigned by EPA, used to
 Code.                          identify each laboratory. The code
                                begins with the standard two-character
                                State postal abbreviation; the remaining
                                5 numbers are unique to each laboratory
                                in the State.
15. Sample Event Code........  A code assigned by the PWS for each
                                sample event. This will associate
                                samples with the PWS monitoring plan to
                                allow EPA to track compliance and
                                completeness. Systems must assign the
                                following codes:
                               SE1 = represents samples collected to
                                meet the UCMR monitoring requirement for
                                the first sampling period (all source
                                types).
                               SE2 = represents samples collected to
                                meet the UCMR monitoring requirement for
                                the second sampling period (all source
                                types).
                               SE3 = represents samples collected to
                                meet the UCMR monitoring requirement for
                                the third sampling period (surface water
                                and GWUDI sources only).
                               SE4 = represents samples collected to
                                meet the UCMR monitoring requirement for
                                the fourth sampling period (surface
                                water and GWUDI sources only).
------------------------------------------------------------------------

Subpart E--[Amended]

    4. Section 141.40 is revised to read as follows:


Sec.  141.40  Monitoring requirements for unregulated contaminants.

    (a) General applicability. This section specifies the monitoring 
and quality control requirements that must be followed if you are a 
public water system (PWS) that is subject to the Unregulated 
Contaminant Monitoring Regulation (UCMR), as specified in paragraphs 
(a)(1) and (2) of this section. In addition, this section specifies the 
UCMR requirements for State and Tribal participation. For the purposes 
of this section, PWS ``population served'', ``State'', `` PWS 
Official'', and ``PWS Technical Contact'' are as defined in Sec.  
141.35(a). The determination of whether a PWS is required to monitor 
under this rule is based on the type of system (e.g., community water 
system, non-transient non-community water system, etc.); whether or not 
the system purchases all of its water from another system; and its 
population served as of June 30, 2005.
    (1) Applicability to transient non-community systems. If you own or 
operate a transient non-community water system, you do not have to 
monitor that system for unregulated contaminants.
    (2) Applicability to community water systems and non-transient non-
community water systems.
    (i) Large systems. If you own or operate a wholesale or retail PWS 
(other than a transient non-community system) that serves more than 
10,000 people, and do not purchase your entire water supply as finished 
water from another PWS, you must monitor according to the 
specifications in this paragraph. If you believe that your 
applicability status is different than EPA has specified in the 
notification letter that you received, or if you are subject to UCMR 
requirements and you have not been notified by either EPA or your 
State, you must report to EPA, as specified in Sec.  141.35(b)(1) and 
(2), respectively.
    (A) Assessment Monitoring. You must monitor for the unregulated 
contaminants on List 1 of Table 1, Unregulated Contaminant Monitoring 
Regulation (UCMR) Contaminant List, in paragraph (a)(3) of this 
section. If you serve a population of more than 10,000 people, you are 
required to perform this monitoring regardless of whether or not you 
have been notified by the State or EPA.
    (B) Screening Survey. You must monitor for the unregulated 
contaminants on List 2 (Screening Survey) of Table 1, as specified in 
paragraph (a)(3) of this section, if your system serves 10,001 to 
100,000 people and you are notified by EPA or your State that you are 
part of the State Monitoring Plan for Screening Survey testing. If your 
system serves more than 100,000 people, you are required to conduct 
this Screening Survey testing regardless of whether or not you have 
been notified by the State or EPA.

[[Page 49133]]

    (C) Pre-Screen Testing. You must monitor for the unregulated 
contaminants on List 3 of Table 1, in paragraph (a)(3) of this section, 
if notified by your State or EPA that you are part of the Pre-Screen 
Testing.
    (ii) Small systems. Small PWSs, as defined in this paragraph, will 
not be selected to monitor for any more than one of the three 
monitoring lists provided in Table 1, UCMR Contaminant List, in 
paragraph (a)(3) of this section. EPA will provide sample containers, 
provide pre-paid air bills for shipping the sampling materials, conduct 
the laboratory analysis, and report and review monitoring results for 
all small systems selected to conduct monitoring under paragraphs 
(a)(2)(ii)(A) through (C) of this section. If you own or operate a PWS 
(other than a transient system) that serves 10,000 or fewer people and 
do not purchase your entire water supply from another PWS, you must 
monitor as follows:
    (A) Assessment Monitoring. You must monitor for the unregulated 
contaminants on List 1 of Table 1, in paragraph (a)(3) of this section, 
if you are notified by your State or EPA that you are part of the State 
Monitoring Plan for Assessment Monitoring.
    (B) Screening Survey. You must monitor for the unregulated 
contaminants on List 2 of Table 1, in paragraph (a)(3) of this section, 
if notified by your State or EPA that you are part of the State 
Monitoring Plan for the Screening Survey.
    (C) Pre-Screen Testing. You must monitor for the unregulated 
contaminants on List 3 of Table 1, in paragraph (a)(3) of this section, 
if you are notified by your State or EPA that you are part of the State 
Monitoring plan for Pre-Screen Testing.
    (3) Analytes to be monitored. Lists 1, 2, and 3 of unregulated 
contaminants are provided in the following table:

                                                             Table 1.--UCMR Contaminant List
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                      6--Period during
           1--Contaminant                2--CAS registry     3--Analytical  methods   4--Minimum reporting  5--Sampling  location   which monitoring to
                                             number                     a                   level b                   c                 be completed
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   LIST 1: ASSESSMENT MONITORING CHEMICAL CONTAMINANTS
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Dimethoate......................  60-51-5...............  EPA 527 d.............  0.71 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
2. Terbufos sulfone................  56070-16-7............  EPA 527 d.............  0.44 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
3. 2,2',4,4'-tetrabromodiphenyl      5436-43-1.............  EPA 527 d.............  0.33 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
 ether (BDE-47).
4. 2,2',4,4',5-pentabromodiphenyl    60348-60-9............  EPA 527 d.............  0.92 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
 ether (BDE-99).
5. 2,2',4,4',5,5'-hexabromobiphenyl  59080-40-9............  EPA 527 d.............  0.72 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
 (245-HBB).
6. 2,2',4,4',5,5'-hexabromodiphenyl  68631-49-2............  EPA 527 d.............  0.85 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
 ether (BDE-153).
7. 2,2',4,4',6-pentabromodiphenyl    189084-64-8...........  EPA 527 d.............  0.52 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
 ether (BDE-100).
8. 1,3-dinitrobenzene..............  99-65-0...............  EPA 529 e.............  0.76 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
9. 2,4,6-trinitrotoluene (TNT).....  118-96-7..............  EPA 529 e.............  0.78 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
10. Hexahydro-1,3,5-trinitro-1,3,5-  121-82-4..............  EPA 529 e.............  1.2 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2010.
 triazine (RDX).
11. Perchlorate....................  14797-73-0............  EPA 314.0 f, g........  0.57 [mu]g/L.........  EPTDS................  7/1/2007-6/31/2010.
                                     ......................  EPA 314.1 h...........  .....................  .....................
                                     ......................  EPA 331.0 i...........  .....................  .....................
                                     ......................  EPA 332.0 j...........  .....................  .....................
------------------------------------
                                                     LIST 2: SCREENING SURVEY CHEMICAL CONTAMINANTS
                                                       Acetanilide Pesticide Degradation Products
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Acetochlor ESA..................  187022-11-3...........  EPA 535 k.............  1.4 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2009.
2. Acetochlor OA...................  184992-44-4...........  EPA 535 k.............  1.5 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2009.
3. Alachlor ESA....................  142363-53-9...........  EPA 535 k.............  1.0 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2009.
4. Alachlor OA.....................  171262-17-2...........  EPA 535 k.............  1.6 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2009.
5. Metolaclor ESA..................  171118-09-5...........  EPA 535 k.............  1.1 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2009.
6. Metolachlor OA..................  152019-73-3...........  EPA 535 k.............  1.5 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2009.
------------------------------------
                                                         Acetanilide Pesticide Parent Compounds
--------------------------------------------------------------------------------------------------------------------------------------------------------
7. Acetochlor......................  34256-82-1............  EPA l.................  2.0 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2009.
8. Alachlor........................  15972-60-8............  EPA l.................  1.6 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2009.
9. Metolachlor.....................  51218-45-2............  EPA l.................  1.0 [mu]g/L..........  EPTDS................  7/1/2007-6/31/2009.
------------------------------------
                                                                      Nitrosamines
--------------------------------------------------------------------------------------------------------------------------------------------------------
10. N-nitroso-diethylamine (NDEA)..  55-18-5...............  EPA 521 m.............  0.0046 [mu]g/L.......  DSMRT and EPTDS......  7/1/2007-6/31/2009.

[[Page 49134]]

 
11. N-nitroso-dimethylamine (NDMA).  62-75-9...............  EPA 521 m.............  0.0024 [mu]g/L.......  DSMRT and EPTDS......  7/1/2007-6/31/2009.
12. N-nitroso-di-n-butylamine        924-16-3..............  EPA 521 m.............  0.0035 [mu]g/L.......  DSMRT and EPTDS......  7/1/2007-6/31/2009.
 (NDBA).
13. N-nitroso-di-n-propylamine       621-64-7..............  EPA 521 m.............  0.0072 [mu]g/L.......  DSMRT amd EPTDS......  7/1/2007- 6/31/2009.
 (NDPA).
14. N-nitroso-methylethylamine       10595-95-6............  EPA 521 m.............  0.0034 [mu]g/L.......  DSMRT and EPTDS......  7/1/2007-6/31/2009.
 (NMEA).
15. N-nitroso-pyrrolidine (NPYR)...  930-55-2..............  EPA 521 m.............  0.0022 [mu]g/L.......  DSMRT and EPTDS......  7/1/2007-6/31/2009.
------------------------------------
                                LIST 3: PRE-SCREEN TESTING TO BE SAMPLED AFTER NOTICE OF ANALYTICAL METHODS AVAILABILITY
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Reserved n......................  Reserved n............  Reserved n............  Reserved n...........  Reserved n...........  Reserved.n
--------------------------------------------------------------------------------------------------------------------------------------------------------
Column headings are:
1--Contaminant: the name of the contaminant to be analyzed.
2--CAS (Chemical Abstract Service) Registry Number or Identification Number: a unique number identifying the chemical contaminants.
3--Analytical Methods: method numbers identifying the methods that must be used to test the contaminants.
4--Minimum Reporting Level: the value and unit of measure at or above which the concentration of the contaminant must be measured using the approved
  analytical methods.
5--Sampling Location: the locations within a PWS at which samples must be collected.
6--Period During Which Monitoring to Be Completed: the years during which the sampling and testing are to occur for the indicated contaminant.
The analytical procedures shall be performed in accordance with the documents associated with each method (per the following footnotes). The
  incorporation by reference of the following documents listed in footnotes d-m was approved by the Director of the Federal Register in accordance with
  5 U.S.C. 552(a) and 1 CFR part 51. Information on how to obtain these documents can be provided by the Safe Drinking Water Hotline at (800) 426-4791.
  Documents may be inspected at EPA's Drinking Water Docket, 1301 Constitution Avenue, NW., EPA West, Room B102, Washington, DC 20460, Telephone: (202)
  566-2426; or at the National Arcives and Records Administration (NARA). For information on availability of this material at NARA, call 202-741-6030,
  or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations_html.
a The version of the EPA methods which you must follow for this Regulation are listed in d-m as follows.
b The Minimum Reporting Level (MRL) was established by EPA by adding the mean of the Lowest Concentration Minimum Reporting Levels (LCMRL) determined
  according to the procedure detailed in ``Statistical Protocol for the Determination of The Single-Laboratory Lowest Concentration Minimum Reporting
  Level (LCMRL) and Validation of the Minimum Reporting Level (MRL)'' by the primary and secondary laboratories conducting the development and
  validation of the analytical method to three times the difference of the LCMRLs. If LCMRL data from three or more laboratories were available, the MRL
  was established by EPA by adding three times the standard deviation of the LCMRLs to the mean of the LCMRLs. Note that EPA Methods 314.0 and 525.2
  were developed prior to UCMR 2, hence the LCMRLs were not determined for analytes determined by these methods.
c Sampling must occur at entry points to the distribution system (EPTDSs) after treatment is applied that represent each non-emergency water source in
  routine use over the 12-month period of monitoring. See 40 CFR 141.35(c)(3) for an explanation of the requirements related to use of representative
  EPTDSs. Sampling for nitrosamines on List 2 must also occur at the disinfection byproduct distribution system maximum residence time (DSMRT) sampling
  locations as defined in 40 CFR 141.132(b)(1)(i) and at EPTDSs sampling locations. If a treatment plant/water source is not subject to the sampling
  required in 40 CFR 141.132(b)(1), then the samples for nitrosamines must be collected only at the EPTDS location.
EPA Method 527 d ``Determination of Selected Pesticides and Flame Retardants in Drinking Water by Solid Phase Extraction and Capillary Column Gas
  Chromatography/Mass Spectrometry (GC/MS)'' is available at http://www.epa.gov/safewater/methods/sourcalt.html.
EPA Method 529 e ``Determination of Explosives and Related Compounds in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography/
  Mass Spectrometry (GC/MS)'' is available at http://www.epa.gov/nerlcwww/ordmeth.htm.
EPA Method 314.0 f ``Determination of Perchlorate in Drinking Water Using Ion Chromatography'' is available 
at http://www.epa.gov/safewater/methods/sourcalt.html.
g All perchlorate samples must be collected using the sterile technique required in Methods 314.1, 331.0, or 332.0.
h EPA Method 314.1 ``Determination of Perchlorate in Drinking Water Using Inline Column Concentration/Matrix Elimination Ion Chromatography with
  Suppressed Conductivity Detection'' is available 
  at http://www.epa.gov/safewater/methods/sourcalt.html.
i EPA Method 331.0 ``Determination of Perchlorate in Drinking Water by Liquid Chromatography Electrospray Ionization Mass Spectrometry'' is available at
  http://www.epa.gov/safewater/methods/sourcalt.html.
j EPA Method 332.0 ``Determination of Perchlorate in Drinking Water Using Ion Chromatography with Suppressed Conductivity and Electrospray Ionization
  Mass Spectrometry'' is available at http://www.epa.gov/nerlcwww/ordmeth.htm.
k EPA Method 535, Revision 1.1'' Measurement of Chloroacetanilide and Other Acetamide Herbicide Degradates in Drinking Water by Solid Phase Extraction
  and Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS)'' is available at http://www.epa.gov/nerlcwww/ordmeth.htm.
l EPA Method 525.2 ``Determination of Organic Compounds in Drinking Water by Liquid-Solid Extraction and Capillary Column Gas Chromatography/Mass
  Spectrometry'' is available at http://www.NEMI.gov.
m EPA Method 521 ``EPA Method 521: Determination of Nitrosamines in Drinking Water by Solid Phase Extraction and Capillary Column Gas Chromatography
  with Large Volume Injection and Chemical Ionization Tandem Mass Spectrometry (MS/MS)'' is available at http://www.epa.gov/nerlcwww/ordmeth.htm.
n To be determined at a later time.

    (4) Sampling requirements--
    (i) Large systems. If you serve more than 10,000 people and meet 
the UCMR applicability criteria specified in paragraph (a)(2)(i) of 
this section, you must comply with the requirements specified in 
paragraphs (a)(4)(i)(A) through (I) of this section. Your samples must 
be collected according to the schedule that you are assigned by EPA or 
your State, or the schedule that you revised using EPA's electronic 
data reporting system on or before [DATE 210 DAYS AFTER PUBLICATION OF 
THE FINAL RULE]. Your schedule must

[[Page 49135]]

follow both the timing and frequency of monitoring specified in Tables 
1 and 2 of this section.
    (A) Monitoring period. You must collect the samples in one 
continuous 12-month period for List 1 Assessment Monitoring, and, if 
applicable, for List 2 Screening Survey, or List 3 Pre-Screen Testing, 
during the time frame indicated in column 6 of Table 1, in paragraph 
(a)(3) of this section. As specified in Sec.  141.35(c)(5), you must 
contact EPA if you believe you cannot conduct monitoring according to 
your schedule.
    (B) Frequency. You must collect the samples within the time frame 
and according to the frequency specified by contaminant type and water 
source type for each sampling location, as specified in Table 2, in 
paragraph (a)(4)(i)(B).

                      Table 2.--Monitoring Frequency by Contaminant and Water Source Types
----------------------------------------------------------------------------------------------------------------
                                                                       Time frame
           Contaminant type                  Water source type          (months)             Frequency
----------------------------------------------------------------------------------------------------------------
Chemical.............................  Surface water or ground water           12  You must monitor for 4
                                        under the direct influence                  consecutive quarters. Sample
                                        of surface water (GWUDI)                    events must occur 3 months
                                        (includes all sampling                      apart.
                                        locations for which some or
                                        all of the water comes from
                                        a surface water or GWUDI
                                        source).
                                       Ground water.................           12  You must monitor twice in a
                                                                                    consecutive 12-month period.
                                                                                    Sample events must occur 6
                                                                                    months apart.
----------------------------------------------------------------------------------------------------------------

    (C) Location. You must collect samples for each List 1 Assessment 
Monitoring contaminant, and, if applicable, for each List 2 Screening 
Survey, or List 3 Pre-Screen Testing contaminant, as specified in Table 
1, in paragraph (a)(3) of this section; samples must be collected at 
each sample point that is specified in column 5 of that table. If you 
are a ground water system with multiple EPTDSs, and you request and 
receive approval from EPA or the State for sampling at representative 
EPTDS(s), as specified in Sec.  141.35(c)(3), you must collect your 
samples from the approved representative sampling location(s). Systems 
conducting Screening Survey monitoring must also sample for 
nitrosamines at the disinfection byproduct distribution system maximum 
residence time (DSMRT) sampling location(s) if they are subject to 
sampling requirements in Sec.  141.132(b)(1).
    (D) Sampling instructions. For each List 1 Assessment Monitoring 
contaminant, and, if applicable, for each List 2 Screening Survey, or 
List 3 Pre-Screen Testing contaminant, you must follow the sampling 
procedure for the method specified in column 3 of Table 1, in paragraph 
(a)(3) of this section. In addition, you must not composite (that is, 
combine, mix, or blend) the samples; you must collect, preserve, and 
test each sample separately. If you are using EPA Method 314.0 for 
analysis of perchlorate, you must collect the samples using the sterile 
techniques that are described in any 1 of the other 3 perchlorate 
methods, as specified in Table 1, in paragraph (a)(3) of this section.
    (E) Sample collection and shipping time. If you must ship the 
samples for testing, you must collect the samples early enough in the 
day to allow adequate time to send the samples for overnight delivery 
to the laboratory. You should not collect samples on Friday, Saturday, 
or Sunday because sampling on these days may not allow samples to be 
shipped and received at the laboratory at the required temperature, 
unless you have made special arrangements with your laboratory to 
receive the samples.
    (F) Analytical methods. For each contaminant, you must use the 
analytical methods for List 1, and, if applicable, for List 2, that are 
specified in column 3 of Table 1, in paragraph (a)(3) of this section; 
report values at or above the minimum reporting levels for List 1, and, 
if applicable, for List 2 Screening Survey, or List 3 Pre-Screen 
Testing, that are specified in column 4 of Table 1, in paragraph (a)(3) 
of this section; and conduct the quality control procedures specified 
in paragraph (a)(5) of this section.
    (G) Laboratory errors or sampling deviations. If an error occurs 
either at the laboratory which precludes its reporting of valid data, 
or in sampling for a listed contaminant, you must resample within 14 
days of observing the occurrence of the error using the procedures 
specified for the method. (This resampling is not for confirmation 
sampling, but to correct the sampling or laboratory error.)
    (H) Analysis. For the List 1 contaminants, and, if applicable, List 
2 Screening Survey, or List 3 Pre-Screen Testing contaminants, 
identified in Table 1, paragraph (a)(3) of this section, you must 
arrange for testing by a laboratory that has been approved by EPA 
according to requirements in paragraph (a)(5)(ii) of this section.
    (I) Review and reporting of results. After you have received the 
laboratory results, you must review, approve, and submit the system 
information, and sample collection data and test results. You must 
report the results as provided in Sec.  141.35(c)(6).
    (ii) Small systems. If you serve 10,000 or fewer people and are 
notified that you are part of the State Monitoring Plan for Assessment 
Monitoring, Screening Survey or Pre-Screen monitoring, you must comply 
with the requirements specified in paragraphs (a)(4)(i)(A) through (H) 
of this section. If EPA or the State informs you that they will be 
collecting your UCMR samples, you must assist them in identifying the 
appropriate sampling locations and in taking the samples.
    (A) Monitoring period and frequency. You must collect samples at 
the times specified for you by the State or EPA. Your schedule must 
follow both the timing of monitoring specified in Table 1, List 1, and, 
if applicable, List 2, and the frequency of monitoring in Table 2 of 
this section.
    (B) Location. You must collect samples at the locations specified 
for you by the State or EPA.
    (C) Sample kits. You must store and maintain the sample collection 
kits sent to you by the UCMR Sampling Coordinator in accordance with 
the kit's instructions. The sample kit will include all necessary 
containers, packing materials and cold packs, instructions for 
collecting the sample and sample treatment (such as dechlorination or 
preservation), report forms for each sample, contact name and telephone 
number for the laboratory, and a prepaid return shipping docket and 
return address label. If any of the materials listed in the kit's 
instructions are not included in the kit or arrive damaged, you must 
notify

[[Page 49136]]

the UCMR Sampling Coordinator who sent you the sample collection kits.
    (D) Sampling instructions. You must comply with the instructions 
sent to you by the State or EPA concerning the use of containers, 
collection (how to fill the sample bottle), dechlorination and/or 
preservation, and sealing and preparation of sample and shipping 
containers for shipment. You must not composite (that is, combine, mix, 
or blend) the samples. You also must collect, preserve, and test each 
sample separately. You must also comply with the instructions sent to 
you by the UCMR Sampling Coordinator concerning the handling of sample 
containers for specific contaminants.
    (E) Sampling deviations. If you do not collect a sample according 
to the instructions provided to you for a listed contaminant, you must 
report the deviation within 7 days of the scheduled monitoring on the 
sample reporting form, as specified in Sec.  141.35(d)(2). A copy of 
the form must be sent to the laboratory with the samples, and to the 
UCMR Sampling Coordinator. You must resample following instructions 
that you will be sent from the UCMR Sampling Coordinator or State.
    (F) Duplicate samples. EPA will select systems in the State 
Monitoring Plan that must collect duplicate samples for quality 
control. If your system is selected, you will receive two sample kits 
for an individual sampling location that you must use. You must use the 
same sampling protocols for both sets of samples, following the 
instructions in the duplicate sample kit.
    (G) Sampling forms. You must completely fill out each of the 
sampling forms and bottles sent to you by the UCMR Sampling 
Coordinator, including data elements listed in Sec.  141.35(e) for each 
sample. If you are conducting Assessment Monitoring, you must include 
elements 1 through 5, and 7; and if you are conducting Screening 
Survey, you must include elements 1 through 7. You must sign and date 
the sampling forms.
    (H) Sample collection and shipping. You must collect the samples 
early enough in the day to allow adequate time to send the samples for 
overnight delivery to the laboratory. You should not collect samples on 
Friday, Saturday, or Sunday because sampling on these days may not 
allow samples to be shipped and received at the laboratory at the 
required temperature unless you have made special arrangements with EPA 
for the laboratory to receive the samples. Once you have collected the 
samples and completely filled in the sampling forms, you must send the 
samples and the sampling forms to the laboratory designated on the air 
bill.
    (5) Quality control requirements. If your system serves more than 
10,000 people, you must ensure that the quality control requirements 
listed below are met during your sampling procedures and by the 
laboratory conducting your analyses. You must also ensure that all 
method quality control procedures and all UCMR quality control 
procedures are followed.
    (i) Sample collection/preservation. You must follow the sample 
collection and preservation requirements for the specified method for 
each of the contaminants in Table 1, in paragraph (a)(3) of this 
section. If you are using EPA Method 314.0 for analysis of perchlorate, 
you must collect the samples using the sterile techniques that are 
described in any 1 of the other 3 perchlorate methods, as specified in 
Table 1, in paragraph (a)(3) of this section. These requirements 
specify sample containers, collection, dechlorination, preservation, 
storage, sample holding time, and extract storage and/or holding time 
that you must assure that the laboratory follow.
    (ii) Laboratory approval for Lists 1 and 2. To be approved to 
conduct UCMR testing, the laboratory must be certified under Sec.  
141.28 for one or more compliance analyses; demonstrate for each 
analytical method it plans to use for UCMR testing that it can meet the 
Initial Demonstration of Capability (IDC) requirements specified in 
column 3 of Table 1, in paragraph (a)(3) of this section; and 
successfully participate in the UCMR Proficiency Testing (PT) Program 
administered by EPA for each analytical method it plans to use for UCMR 
testing. UCMR laboratory approval decisions will be granted on an 
individual method basis for the methods listed in column 3 of Table 1 
in paragraph (a)(3) of this section for List 1, List 2, and List 3 
contaminants. Laboratory approval is contingent upon the capability of 
the laboratory to post monitoring data to the EPA electronic data 
reporting system. To participate in the UCMR Laboratory Approval 
Program, the laboratory must complete and submit the necessary 
registration forms by [INSERT DATE 90 DAYS AFTER PUBLICATION OF THE 
FINAL RULE]. Correspondence must be addressed to: UCMR 2 Laboratory 
Approval Coordinator, USEPA, Technical Support Center, 26 West Martin 
Luther King Drive (MS 140), Cincinnati, OH 45268; or e-mailed to EPA at 
[email protected].
    (iii) Minimum Reporting Level. The Minimum Reporting Level (MRL) is 
the lowest analyte concentration for which future recovery is predicted 
to fall, with high confidence (99%), between 50% and 150% recovery.
    (A) Validation of laboratory performance. Your laboratory must be 
capable of quantifying each contaminant listed in Table 1, at or below 
the MRL specified in column 4 of Table 1, in paragraph (a)(3) of this 
section. You must ensure that the laboratory completes and has on file 
and available for your inspection, records of two distinct procedures. 
First, your laboratory must have conducted an IDC involving replicate 
analyses at or below the MRL as described in this paragraph. Second, 
for each day that UCMR analyses are conducted by your laboratory, a 
validation of its ability to quantify each contaminant, at or below the 
MRL specified in column 4 of Table 1, in paragraph (a)(3) of this 
section, following the procedure listed in paragraph (a)(5)(iii)(B) of 
this section, must be performed. The procedure for validation of 
laboratory performance at or below the MRL is as follows:
    (1) All laboratories using EPA drinking water methods under UCMR 
must demonstrate that they are capable of meeting data quality 
objectives (DQOs) at or below the MRL listed in Table 1, column 4, in 
paragraph (a)(3) of this section.
    (2) The MRL, or any concentration below the MRL, at which 
performance is being evaluated, must be contained within the range of 
calibration. The calibration curve regression model and the range of 
calibration levels that is used in these performance validation steps 
must be used in all routine sample analyses used to comply with this 
regulation. Only straight line or quadratic regression models are 
allowed. The use of either weighted or unweighted models is permitted. 
The use of cubic regression models are not permitted.
    (3) Replicate analyses of at least seven (7) fortified samples in 
reagent water must be performed at or below the MRL for each analyte, 
and must be processed through the entire method procedure (i.e., 
including extraction, where applicable and with all preservatives).
    (4) A prediction interval of results (PIR), which is based on the 
estimated arithmetic mean of analytical results and the estimated 
sample standard deviation of measurement results, must be determined by 
Equation 1:

[[Page 49137]]

[GRAPHIC] [TIFF OMITTED] TP22AU05.004

Where:

t is the Student's t value with df degrees of freedom and confidence 
level (1-a),
s is the sample standard deviation of n replicate samples fortified at 
the MRL,
n is the number of replicates.

    (5) The values needed to calculate the PIR using Equation 1 are: 
number of replicates (n); Student's t value with a two-sided 99% 
confidence level for n number of replicates; the average (mean) of at 
least seven replicates; and the sample standard deviation. Factor 1 is 
referred to as the Half Range PIR (HRPIR). For a certain 
number of replicates and for a certain confidence level in Student's t, 
this factor is constant, and can be tabulated according to replicate 
number and confidence level for the Student's t. Table 3 in this 
paragraph lists the constant factor (C) for replicate sample numbers 7 
through 10 with a confidence level of 99% for Student's t.
[GRAPHIC] [TIFF OMITTED] TP22AU05.005

    (6) The HRPIR is calculated by Equation 2:
    [GRAPHIC] [TIFF OMITTED] TP22AU05.006
    
    (7) The PIR is calculated by Equation 3:
    [GRAPHIC] [TIFF OMITTED] TP22AU05.007
    

   Table 3.--The Constant Factor (C) To Be Multiplied by the Standard
        Deviation To Determine the Half Range Interval of the PIR
                   [Student's t 99% confidence level]1
------------------------------------------------------------------------
                                              Constant factor (C) to be
          Replicates            Degrees of   multiplied by the standard
                                 freedom              deviation
------------------------------------------------------------------------
7............................            6                         3.963
8............................            7                         3.711
9............................            8                         3.536
10...........................            9                        3.409
------------------------------------------------------------------------
1 The critical t-value for a two-sided 99% confidence interval is
  equivalent to the critical t-value for a one-sided 99.5% confidence
  interval, due to the symmetry of the t-distribution. PIR = Prediction
  Interval of Results.

    (8) The lower and upper result limits of the PIR must be converted 
to percent recovery of the concentration being tested. To pass criteria 
at a certain level, the PIR lower recovery limits cannot be lower than 
the lower recovery limits of the quality control (QC) interval (50%), 
and the PIR upper recovery limits cannot be greater than the upper 
recovery limits of the QC interval (150%). When the PIR recovery limits 
fall outside of either bound of the QC interval of recovery (higher 
than 150% or less than 50%), laboratory performance is not validated at 
the concentration evaluated. If the PIR limits are contained within 
both bounds of the QC interval, laboratory performance is validated for 
that analyte.
    (B) Quality control requirements for validation of laboratory 
performance at or below the MRL.
    (1) You must ensure that the calibration curve regression model and 
that the range of calibration levels that are used in these performance 
validation steps are used in future routine sample analysis. Only 
straight line or quadratic regression models are allowed.
    (2) You must ensure, once your laboratory has performed an IDC as 
specified in each analytical method (demonstrating that DQOs are met at 
or below an MRL), that a daily performance check is performed for each 
analyte and method. A single sample, spiked at or below the MRL for 
each analyte, must be processed through the entire method procedure. 
The measured concentration for each analyte must be converted to a 
percent recovery, and if the recovery is within 50%-150% (inclusive), 
the daily performance of the laboratory has been validated. The results 
for any analyte for which 50%-150% recovery cannot be demonstrated 
during the daily check are not valid. Laboratories may elect to re-run 
the daily performance check sample if the performance for any analyte 
or analytes cannot be validated. If performance is validated for these 
analytes, then the laboratory performance is considered validated. 
Alternatively, the laboratory may re-calibrate and repeat the 
performance validation process for all analytes. Laboratories 
performing perchlorate analyses using EPA Method 314.0 must, in 
addition to the quality control specified in that method, successfully 
monitor the Laboratory Synthetic Sample Matrix Blank and the MRL 
Laboratory Fortified Synthetic Sample Matrix, as specified in Section 
9.3.2 and 9.3.4 of EPA Method 314.1, prior to analysis of samples. The 
MRL Laboratory Fortified Synthetic Sample Matrix is intended as a daily 
MRL check and only must be run once per analysis batch.
    (iv) Laboratory fortified sample matrix and laboratory fortified 
sample matrix duplicate. You must ensure that your laboratory prepares 
and analyzes the Laboratory Fortified Sample Matrix (LFSM) sample for 
accuracy and Laboratory Fortified Sample Matrix Duplicate (LFSMD) 
samples for precision to determine method accuracy and precision for 
all contaminants in Table 1, in paragraph (a)(3) of this section. LFSM/
LFSMD samples must be prepared using a sample collected and analyzed in 
accordance with UCMR 2 requirements and analyzed at a

[[Page 49138]]

frequency of 5% (or 1 LFSM/LFSMD set per every 20 samples) or with each 
sample batch, whichever is more frequent. In addition, the LFSM/LFSMD 
fortification concentrations must be alternated between a low-level 
fortification and mid-level fortification approximately 50% of the 
time. (For example: a set of 40 samples will require preparation and 
analysis of 2 LFSM/LFSMD sets. The first set must be fortified at 
either the low-level or mid-level, and the second set must be fortified 
with the other standard, either the low-level or mid-level, whichever 
was not used for the initial LFSM/LFSMD set.) The low-level LFSM/LFSMD 
fortification concentration must be within 20% of the MRL 
for each contaminant (e.g., for an MRL of 1.0 [mu]g/L the acceptable 
fortification levels must be between 0.80 [mu]g/L and 1.2 [mu]g/L). The 
mid-level LFSM/LFSMD fortification concentration must be within 20% of the mid-level calibration standard for each contaminant, 
and should represent, where possible and where the laboratory has data 
from previously analyzed samples, an approximate average concentration 
observed in previous analyses of that analyte. There are no acceptance 
criteria specified for LFSM/LFSMD analyses. All LFSM/LFSMD data are to 
be reported.
    (v) Detection Confirmation. Results greater than or equal to the 
MRLs specified in column 4 of Table 1 in paragraph (a)(3) of this 
section, that are obtained using Methods 314.0 or 314.1, must be 
confirmed before being reported. Results using these methods must be 
confirmed by Methods 331.0 or 332.0 or by second column confirmation as 
detailed in Method 314.1. If confirmation is being performed using the 
second column specified in Method 314.1, the laboratory must use one of 
the following confirming techniques: perform single point calibration 
of the second chromatographic column for confirmation purposes only as 
long as the calibration standard is at a concentration within 50% of the concentration determined by the initial analysis; or 
perform a three (3) point calibration with single point daily 
calibration verification of the second chromatographic column 
regardless of whether that verification standard concentration is 
within 50% of sample response. However, this calibration 
must bracket the concentration of the contaminant observed. The 
concentration obtained for the primary column must be reported; if the 
concentration observed on the primary column is within 2 times the MRL 
and the quantitation of both columns is within 50%, or if 
the concentration observed on the primary column is greater than 2 
times the MRL and the quantitation of both columns is within 30%. If the quantitation obtained from both columns is not within 
50% and the concentration observed on the primary column is 
within 2 times the MRL, or if the quantitation obtained from both 
columns is not within 30% and the concentration observed on 
the primary column greater than 2 times the MRL, the result is to be 
reported as ``not reported due to matrix interference,'' as specified 
in Table 1, in Sec.  141.35(e). If confirmation is being performed 
using either Method 331.0 or 332.0, then the laboratory must report the 
Method 331.0 or 332.0 result.
    (vi) Method defined quality control. You must ensure that your 
laboratory performs Laboratory Fortified Blanks and Laboratory 
Performance Checks, as appropriate to the method's requirements, for 
those methods listed in Table 1, column 3, in paragraph (a)(3) of this 
section. Each method specifies acceptance criteria for these QC checks.
    (vii) Reporting. You must ensure that the laboratory you use 
reports the analytical results and other data, with the required data 
listed in Table 1, in Sec.  141.35(e). You must require your laboratory 
to submit these data electronically to the State and EPA using EPA's 
electronic data reporting system (http://www.epa.gov/safewater/ucmr/ucmr2/reporting.html) within 120 days from the sample collection date. 
You have 60 days from when the laboratory posts the data to then 
review, approve, and submit the data to the State and EPA, via EPA's 
electronic data reporting system. If you do not electronically approve 
and submit the laboratory data to EPA within 60 days of the 
laboratory's posting to EPA's electronic reporting system, the data 
will be considered approved and final for EPA review.
    (6) Violation of this rule--
    (i) Monitoring violations. Any failure to monitor in accordance 
with Sec.  141.40(a)(3)-(5) is a monitoring violation.
    (ii) Reporting violations. Any failure to report in accordance with 
Sec.  141.35 is a reporting violation.
    (b) Requirements for State and Tribal participation--
    (1) Governors' petition for additional contaminants. The Safe 
Drinking Water Act allows Governors of seven (7) or more States to 
petition the EPA Administrator to add one or more contaminants to the 
UCMR Contaminant List in paragraph (a)(3) of this section. The petition 
must clearly identify the reason(s) for adding the contaminant(s) to 
the monitoring list, including the potential risk to public health, 
particularly any information that might be available regarding 
disproportional risks to the health and safety of children, the 
expected occurrence documented by any available data, any analytical 
methods known or proposed to be used to test for the contaminant(s), 
and any other information that could assist the Administrator in 
determining which contaminants present the greatest public health 
concern and should, therefore, be included on the UCMR Contaminant List 
in paragraph (a)(3) of this section.
    (2) State-wide waivers. You can waive monitoring requirements only 
with EPA approval and under very limited conditions. Conditions and 
procedures for obtaining a waiver are as follows:
    (i) Application. You may apply to EPA for a State-wide waiver from 
the unregulated contaminant monitoring requirements for PWSs serving 
more than 10,000 people. To apply for such a waiver, you must submit an 
application to EPA that includes the following information: the list of 
contaminants on the UCMR Contaminant List for which you request a 
waiver, along with documentation for each contaminant in your request 
demonstrating that the contaminants or their parent compounds do not 
occur naturally in your State, and certifying that during the past 15 
years they have not been used, applied, stored, disposed of, released, 
or detected in the source waters or distribution systems in your State.
    (ii) Approval. EPA will review your application and notify you 
whether it accepts or rejects your request. You must receive written 
approval from EPA before issuing a State-wide waiver.

[FR Doc. 05-16385 Filed 8-19-05; 8:45 am]
BILLING CODE 6560-50-P